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NFRC Simulation Manual - National Fenestration Rating Council

1. Created by Company Client Make sure to set the Cross Section Type both THERM and WINDOW Cross Section Type Sil use this value for calculation Notes settings Figure 6 2 The Cross Section Type value from the THERM File Properties is used by the ISO 15099 models to determine the gravity vector and also in WINDOW to determine the method for calculating the Condensation Resistance values 6 4 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 6 MODELING FRAME AND EDGE HEAT TRANSFER WITH THERM 6 3 Draw the Cross Sections 6 3 3 Cross Section Orientation For NFRC simulations using THERM all cross sections shall be oriented in a vertical direction i e all the glazing systems must be pointing either up or down not horizontally The exception is for skylights which are modeled at a 20 degree tilt see Section 8 5 for a discussion of modeling skylights When creating the cross section the frame components may be drawn horizontally if that is easiest i e if the DXF file is drawn that way but before importing the glazing system rotate the cross section so that the glazing will come in either up or down So for example jamb cross sections can be drawn horizontally but they must be rotated into a vertical position for modeling Figure 6 3 shows how a DXF file might be drawn The horizontal jamb and meeting rail sections can be drawn horizontally as in the DXF file until the point of importing the
2. inyl mdb File Edit Libraries Record Tools Yiew Help Cee SSO SB herp nilpae mi OF FZ List Dei o gt Cale F9 Name Vinyl 3mm low E No Dis Mode NFRC New jl Type Fixed picture gt gt Copy T Width 1200 mm Dete Height 1500 mm Save Area 1 800 m2 101 x R Best glazing option Report Tilt 30 Environmental Conditions T Dividers NFRC 100 2010 Dividers l SHGC and T detail x Display mode Normal Total Window Results U factor 1 8095 W m2 K No Generic Generic ent to display characteristics below Dpwiders Dpyviders Dypwiders SHGC 0 5254 ee Nam one PDD rm ee 15 05000 38 10000 giba Ucenter 17A W mK SHGCO 0 00203 0 00495 0 00771 on 83 Detel nyes 2 sc 0 698 SHGC1 086426 0 77823 0 69688 Area 1 249 m2 sHGC 0 607 VTO Click the Detail button to Edge area 0308 m2 Vte 0 746 0 00000 0 00000 0 00000 display the SHGCo WTI 0 86224 0 77328 0 68917 SHGC VTo VT values 7 Be Mode NFRC SI Nu a x ee Figure 9 10 Window Library SHGC and VT values for the best glazing option accessed from the Detail button Table 9 5 SHGCo SHGC1 VTo and VT data for the best glazing option in this product line Clear Air Low E Dividers Dividers lt 25 4 mm modeled at gt 25 4 mm modeled at No Divid j en 19 5 mm 1 0 38 1 mm gt 1 5 modeled modeled
3. Choose menu option File Save filename or Right click to display the pop up menu and select the option Save filename If the layer or system you saved had components or if the save operation fails you will be asked Do you want to view the details of the save operation If you answer yes you can view information about components that were saved to the user database and components that were not saved to the user database along with an explanation of why some components were not saved Note to change the filename and save in one operation choose menu option Save As instead Note You cannot save data for a layer with the same filename as another layer in the IGDB or your current user database If a conflict is detected Optics will ask you to rename the layer before saving it or cancel the import The most common reason a component is not saved is that its filename already exists in the IGDB or user database In this case Optics assumes that the component layer information is already available and does not need to be saved again THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 126 8 SPECIAL CASES 8 11 Creating a Laminate in Optics for NFRC Glazing System Laminate S Layer HI 2 H3 Miamin lt button to save the Filename CLEAR 015_82 Optiw3 CalcLan a elas sola T pea oe99 0904 lora CONST UCUON solar AF 0o75 ooo 00s zolar Ab lq ay photopic T 0 899 0 879 photopic RF 0 0
4. OSES RB bo tiatr Lage Ol A E U Frame Cavity Surtace v Step 3 Insert the glazing system using the Libraries Glazing Systems menu choice or the F6 key Specify the appropriate values in the dialog boxes such as Orientation Up and then click on the OK button and the glazing system will be imported Ia Step 5 Use the Material Link EEE x feature to fill the polygon Th below the glazing cavity with the same material as Cancel the glazing cavity itself Kleina ersten ei 25 4 mi Fill the space with any CF cavity heioht 1000 mm material on a Select the polygon sight line to bottom of glass fi 5 196 mm Goto Libraries Create Spacer height 9 7790 ran Edge of Glass Dimension Step 4 Link menu option Edge of Glass Dimension 63 5 e 63 5 mm 2 5 inches Insert the With the Eye Dropper Glazing systemheight 150 mm Glazing system height spacer cursor click on the sistance ON an 150 mm 6 0 inches l lag system cavity The Site line to shade edge is only for modeling shading systems and so for NFRC Use nominal glass thickness ratings shall always be 0 Use CR Model for Window Glazing Systems Gap Properties Defaut f Custom Gafi gt oe a a Exterior Boundary Condition Use existing BC from 4 3 Spacer library ego dx dy 0 5 4 6 len 4 6 Step 10 0 mm r Draw PA NFRC 100 2010 Exterior Single spacer for multiple glazings Interior Boundary Condition Material
5. 25 4 mm gt 1 25 4 mm Glazing Option No Dividers modeled at 0 75 modeled at 1 5 Clear Air Clear 0 7017 0 6316 0 5651 9 44 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 9 SAMPLE PROBLEMS 9 4 Problem 3 Flush Mount Skylight 9 4 7 Skylight Drawings The following are detailed drawings for the skylight Head Sill and Jamb 1 913 2 364 Figure 9 41 Dimensioned drawing for the frame Spacer Figure 9 42 Dimensioned drawing for the spacer THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 9 45 9 5 Problem 4 Door 9 SAMPLE PROBLEMS 9 5 Problem 4 Door For this wood stile and rail door calculate the U factor SHGC and VT 9 5 1 Description Door Type Wood stile and rail door Overall Size Width 1000 mm Height 2000 mm Frame Material Wood with a thermal break aluminum sill Glazing System Double glazing 12 7 mm 0 5 overall IG thickness There are four glass options all with two layers of 3 mm 0 129 PPG glass Spacer Type Intercept spacer with butyl sealant on three sides Glazing Tape Wet glazed with silicone on both sides Dividers N A Cross Sections See Section 9 5 7 for drawings of this product 9 5 2 Glazing Matrix The table below shows the glazing matrix that is to be simulated for the door Table 9 24 Matrix of glazing options for the door Glazing Options 12 7 mm 0 5 overall thickness Grid Option Clear 8mm Air Clear 6mm Clea
6. 9 66 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 9 SAMPLE PROBLEMS 9 5 Problem 4 Door Head Figure 9 59 Dimensioned drawing for the head cross section THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 9 67 9 5 Problem 4 Door 9 SAMPLE PROBLEMS Panel Edge Figure 9 60 Dimensioned drawing for the panel edge cross section 9 68 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 9 SAMPLE PROBLEMS 9 5 Problem 4 Door Door Lite 0 625 20 0 092 aaa 1 750 Figure 9 61 Dimensioned drawing for the door lite cross section Spacer Figure 9 62 Dimensioned drawing for the spacer THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 9 69 9 5 Problem 4 Door 9 SAMPLE PROBLEMS 9 70 June 2013 THERME6 3 WINDOW6 3 NFRC Simulation Manual APPENDIX A THE APPLICATION OF ISO 15099 TO NFRC 100 AND 200 Software utilized in computing NFRC U factors NFRC 100 02 and SHGCs NFRC 200 02 will be based on the recently completed ISO 15099 document FDIS September 21 2001 In several cases ISO 15099 suggests that individual national standards will need to be more specific and in other cases the ISO document gives users the choice of two options This document clarifies these specific issues as they are to be implemented in NERC approved software algorithms 1 Section 4 1 For calculating the overall U factor ISO 15099 offers a choice between the linear thermal transmittance 4 1 2 and the area
7. 1 296 Figure 9 25 Dimensioned drawing for the sill vent cross section 9 30 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 9 SAMPLE PROBLEMS 9 3 Problem 2 Aluminum Horizontal Slider Window Sill Fixed 1 284 Figure 9 26 Dimensioned drawing for the sill fixed cross section Jamb Vent Figure 9 27 Dimensioned drawing for the jamb vent cross section THERM6 3 WINDOWG6 3 NFRC Simulation Manual June 2013 9 31 9 3 Problem 2 Aluminum Horizontal Slider Window 9 SAMPLE PROBLEMS Jamb Fixed 1 000 O750 ee A 0 675 Figure 9 28 Dimensioned drawing for the jamb fixed cross section Head Vent mee Figure 9 29 Dimensioned drawing for the head vent cross section 9 32 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 9 SAMPLE PROBLEMS 9 3 Problem 2 Aluminum Horizontal Slider Window e cee R a 2 Figure 9 30 Dimensioned drawing for the head fixed cross section Head Fixed 1 269 Meeting Rail 1 269 ios Figure 9 31 Dimensioned drawing for the meeting rail cross section THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 9 33 9 3 Problem 2 Aluminum Horizontal Slider Window Spacer i 0 7600 I 0 7000 0 0750 s 0 0800 0 3300 e 0 1724 Figure 9 32 Dimensioned drawing for the spacer Divider R0 0310 0 0310 0 9380 1 0000 K 0 2880 0 3500 Figure 9 33 Dimensioned drawing for the divider 9 SAMPLE PROBLEMS 9 34 June 2013
8. 8 4 2 2 Calculate U factor in THERM The steps for importing the glazing system into THERM are explained in more detail below 1 Draw the required frame cross sections such as head sill jambs meeting rails and dividers 2 From the File Properties menu select the appropriate Cross Section Type such as Sill Head Jamb and so forth 3 Import the glazing system with the correct storm window cavity dimensions created in WINDOW in this case the glazing system with the 2 gap Edge of Glass Dimension 63 5 mm 2 5 inch Glazing System Height 150 mm 6 0 inch Exterior Boundary Condition Use existing BC from library select NFRC 100 2010 Exterior Interior Boundary Condition Use convection plus enclosure radiation for glazing system and appropriate convection only boundary condition for the interior frame components E THERM 6 3 Stormwindow sill thm LA File Edit View Draw Libraries Options Calculation Window Help sea EENE S a aA A Aa Step 2 p E ID Name Insert Glazing Glazing System 9 Storm window System from Insert Glazing System xj WINDOW5 H Layers 3 Orientation Up i Ucenter 1 76 Wir F NFRC CMA aes Thickness 72 B44 ae Hazing system width 72 644 Shading layers Mone E height 1000 om a Step 3 mm Set Glazing System properties Edge of Glass Dimension 63 5 mm 2 5 Glazing system Close WINDOW Glazing System Li
9. Down For Jambs set Cross Section to Sill set Gravity Vector to Right The Frame Cavity height is not used by the program for the skylight cross sections as long as the Types are defined properly as shown above so the default value of 1000 mm can be left unchanged Insert the glazing system from WINDOW into the frame cross sections with the Glazing system height field set to 150 mm 6 0 inches and the Edge of Glass Dimension field set to 63 5 mm 2 5 inches The CR cavity height field can be set to any value you can leave it set to the default of 1000 mm because the U factor temperatures not the CR temperatures will be used in WINDOW to calculate the overall CR value Insert the Sill glazing system with orientation up Insert the Head glazing system with orientation down Insert the Jamb glazing system with orientation up Assign the boundary conditions Interior Boundary conditions have the following settings Radiation Model set to AutoEnclosure Frame Boundary Conditions set to the appropriate Interior 20 tilt choices Tilt the cross section 20 degrees from horizontal Fora Sill or Head rotate the entire model 70 degrees clockwise THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 57 8 SPECIAL CASES 8 5 Skylights For Jambs do not rotate the model at all Simulate the skylight cross sections and save them View the U factor for the cross section and make sure the
10. Effective Openness Fraction 1 000 Venetian Blind Slat width 14 8 mm D a m Spacing 12 0 mm _ Tit Tit angle o a degrees Blind thickness 148 mm Rise 0 838 mm a Help Figure 8 192 When a Shading Layer Library record is imported from the CGDB the associated Shade Material Library record is imported automatically THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 204 9 SAMPLE PROBLEMS 9 1 Overview There are four sample problems Problem 1 Vinyl Fixed Window page 9 2 Problem 2 Aluminum Horizontal Sliding Window page 9 16 Problem 3 Flush Mount Skylight page 9 35 Problem 4 Door page 9 46 These sample problems may contain boundary conditions frame cavity conditions and modeling techniques that do not conform to the NFRC modeling rules If this is the case the NFRC modeling rules always take precedence over what is shown in these example problems Also the results shown in these examples may not correspond exactly to results obtained with the WINDOW and THERM programs Please note that some of the drawings provided with these sample problems are proprietary Therefore they shall not be used by anyone for any purpose other than the enclosed sample problems without the prior written consent of NFRC THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 9 1 9 2 Problem 1 Vinyl Fixed Window 9 SAMPLE PROBLEMS 9 2 Problem 1 Vinyl Fixed Window For this fixed vinyl window calculate the
11. F Clear 8mm Argon 95 Clear 6mm 2 88406 0 50791 Low E 3mm Air Clear 8mm 2 33880 0 41189 Low E 3mm Argon 95 Clear mm 1 87978 0 33105 These U factors will be used with the edge of glazing and frame values from THERM to calculate the overall U factor for the door in Section 9 5 6 note that four significant digits have been included as these values will be entered into a spreadsheet in order to calculate overall U factors THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 9 47 9 5 Problem 4 Door 9 SAMPLE PROBLEMS 9 5 4 Edge of glazing and Frame Modeling for U Factor THERM There are a minimum of six and a maximum of eleven cross sections that must be modeled for an entry door system Head Lock Jamb Hinge Jamb Sill Panel Edge Panel Core Door Core Door Lite Head Door Lite Sill Door Lite Hinge Jamb Door Lite Lock Jamb The door in this example has identical cross sections for both jambs so only one jamb model will be required Some simulations required additional lites to be modeled for each door lite cross section head sill and jamb one for each glass option To generate the additional glazing options a base file for each Door Lite cross section has been created using Glazing Option 1 As shown in Figure 9 44 add the remaining options in the Glazing System Options dialog box When the base file is simulated the additional door lite options will be autom
12. Filename HE Product name hd anufacturer Nominal mil Code Reference Butacite MCO10 DuPont hE aa 15PVB6 DUP Butacite MCO10 DuPont a 30P B6 DUP Butacte WlO10 DuPont BOP BE DUP DuPont 30 0637600 Bue PVE A ZURBLUE DUP Butacte 2377 DuPont 30 23577300 Alue Green PE BLUCGREEM DUP Butacite 0360 BRM_DARK DUP photopic Ab DuPont 0360900 Dark Brown E mitF Butacite 0365 DuPont 0365500 Light Brown BRM_LITE DUP PVE Emt p i oes SO 0362500 Medium Brown BRM MEDM DUP solar T E zolar Af zolar Ab photopic T a la E Ge Ge E mu fa a tat im co mp oo photopic Af E E E The selected Interlayer has been added as then 2 layer in the laminate construction Glazing System Laminate Add Glazing Add Interlayer add Embedded Coating Edit Laminate view all Schematic Tie NN eee Buscteencoo furt as foer pve fisPvesoue Buscteencoo Jouet o foer pve SiR prot oo m g a C ou a cu solar T solar Af solar Ab photopic T E E Butacite MCC DuPont BOP BG DUP Butacite 0637 0637600 AZURBLUE DUP Butacte 2377 DuPont 30 2377300 Alue Green PWB BLUGREEN DUOP photopic Rb Butacite 0360 so osso900 Dark Brown BRM DARK DUP EmitF Butacite 0365 0365500 Light Brown BRM_LITE DUP Erith 0 TA Butacte 0362 DuPont 30 0362800 Medium Brown PWE BRN MECM DUP E pho
13. Original file with skipped debridge New file with skipped debridge area set to material with Keff 16 869 W m K Figure 8 85 Original THERM model and new model with new Keff for skipped debridge area Fb 0 0508 m 0 4826 m 0 1053 Fn 1 Fb 1 0 1053 0 8947 Fb Fb 100 0 1053 100 10 53 Skip and debridge needs to be calculated using Isothermal plane procedure Kb 160 W m K conductivity of skipped debridge in this case aluminum THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 88 8 SPECIAL CASES Rt Length conductivity 0 00635 m 0 024 W m K 0 2646 m K W The length is the length of material in a direction of heat flow i e 0 25 as shown in the figure above The air effective conductivity calculated using THERM Kn length Rt 0 00635m 0 2646 m K W 0 024 W m K Fb Kb Fn Kn 0 1053 160 W m K 0 8947 0 024 W m K 16 869 W m K Keff To convert to IP Keff 16 869 0 57782 9 747 Btu hr ft F or in alternative IP Units 116 97 Btu in hr ft F THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 89 8 SPECIAL CASES 8 9 Site Built fenestration products Curtain Walls Window Walls and Sloped Glazing 8 9 Site Built fenestration products Curtain Walls Window Walls and Sloped Glazing A few things to be aware of Review the drawings carefully for non continuous elements These systems tend to have many such elements including shear blocks instal
14. Projected in Glass Plane is selected from the Projection pulldown list as shown in the figure below This will ensure that the projection will be correct for the tilted cross section U fachor delta T Length wima mm Rotation SHGC Exterior 3 5302 29 0 fi 38 411 70 0 Projected in Glass Plane Frame 4 9540 39 0 44 0342 PLAI Projected in Glass Plane Edge 2 2525 29 0 PLAI Tojected in Glass Plane 2 Eror Energy Norm 4 45 Export Figure 8 57 Make sure the Projected in Glass Plane projection option is selected for the tilted cross section There is a circumstance where THERM will not calculate the total frame length correctly and it is necessary to enter a Custom Frame Length into the U factor dialog box above It occurs when a section of an adiabatic boundary overlaps a boundary with a U factor tag in the projected dimension over which the length is being calculated This is explained in detail in Chapter 6 Section 6 6 6 Import the components into the WINDOW Frame Library and Divider Library if appropriate Construct the whole product in the WINDOW Window Library to get the overall product results THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 58 8 SPECIAL CASES 8 5 Skylights 8 5 2 Skylight Mounting Details There are two ways that skylights can be mounted into a roof system either flush mounted also called inset mounted or curb mounted The figures below show
15. Projected in Glass Plane which will allow the program to calculate the correct projected frame dimensions with a tilted cross section Factors OE U factor delta T Length Wir ma E E mm Rotation Frame 4 7604 39 0 43 0003 o n Projected in Glass Plane SHGC Exterior E Of 39 0 48 5854 Projected in Glass Plane 39 0 20 0 Edge 2 5507 63 5 20 0 Projected in Glass Plane Error Energy Norm B334 Export Select Projected in Glass Plane from the pulldown list to replace Projected Y for Frame Edge and SHGC Exterior Figure 8 65 Select the Projected in Glass Plane for the projected frame dimension calculation THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 65 8 SPECIAL CASES 8 5 Skylights In THERM for Head 1 Create the cross section for the Head set the Cross Section Type to Head and import the glazing system facing Down in order to get the Gravity Vector pointing in the proper direction 2 Assign the Boundary Conditions as shown in the figure below 3 Tilt the Head cross section so that it is 20 degrees off horizontal click on the Draw menu Rotate Degree choice and enter 70 degrees Clockwise 4 Check the Gravity Vector View Gravity Arrow which should be pointed down BC NFRC 100 2010 Exterior BC NFRC 100 2010 Exterior U factor tag SHGC Exterior U factor tag None 63 5 mm 2 5 edge of glass 150 mm 6 0 glass he
16. Radiation Model Blackbody U factor tag None U factor tag None BC 3 mm Vinyl U factor Inside Film Radiation Model AutoEnclosure U factor tag Edge K BC Interior Wood Vinyl Frame convection only Radiation Model AutoEnclosure U factor tag Frame a BC NFRC 100 2001 Exterior Radiation Model Blackbody U factor tag SHGC Exterior B BC Adiabatic U factor tag None Ix U factor delta T Length Wma C mm Rotation SHG Exterior 1 4615 33 0 47 5249 fao Projected in Glass Plane Frame 1 6458 39 0 47 625 90 0 Projected in Glass Plane Edge 2 1176 39 0 63 5 30 0 Projected in Glass Plane 3 E sport Eror Energy Norm 7 42 Ent a ala Figure 9 3 THERM cross section and U factor results for the jamb cross section 9 6 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 9 SAMPLE PROBLEMS 9 2 Problem 1 Vinyl Fixed Window Head BC Adiabatic U factor tag None a BC Interior Wood Vinyl Frame convection only Radiation Model AutoEnclosure U factor taq Frame BC NFRC 100 2001 Exterior Radiation Model Blackbody U factor tag SHGC Exterior Modeling Assumptions Cross Section Type Head Gravity Vector Down BC 3 mm Vinyl U factor Inside Film Radiation Model AutoEnclosure U factor tag Edge Gravity eckor e4 BC NFRC 100 2001 Exterior Radiation Model Blackbody U factor tag None BC 3 mm Vinyl U facto
17. Select the Edit Laminate tab in the upper right part of the screen or Choose the menu option File Edit Laminate Load the laminate you wish to edit like you would add a layer into any layer position the current laminate will be cleared and the saved laminate loaded Note You cannot edit laminates in Glazing mode you must switch to Laminate mode first In order to use the edited laminate in a glazing system save the laminate to the user database switch to Glazing mode and re load the laminate layer into the glazing system from the user database Note You cannot use a laminate as a component of another laminate THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 123 8 SPECIAL CASES 8 11 Creating a Laminate in Optics for NFRC 8 11 3 12 Calculation Warnings for Laminates The optical properties of most laminates without coatings can be calculated without generating warnings except that it is likely that some components will not have spectral data across the whole range of the selected wavelength set see 8 11 3 2 Wavelength Sets so the wavelength set will be truncated 8 11 3 13 Viewing Calculation Warnings for Laminates To view calculation warnings for a laminate Select the laminate by clicking on the Lamin layer button Select the Warnings tab The example below shows a warning message that says Results could not be calculated at all wavelengths in the selected wavelength s
18. Skylights are modeled in the same manner as other window products with separate THERM files for the sill head jamb and so forth See Section 8 5 of this manual for detailed instructions on modeling skylights For this example we will assume that the skylight is flush mounted The following table shows the files for this example Table 9 18 Files associated with the skylight example Cross Section DXF Filename THERM Filename Sill Skylight Frame dxf SL thm Head Skylight Frame dxf The table below shows the resulting U factors for the skylight cross sections Table 9 19 THERM results for the skylight cross sections ee Frame U Factor Edge U Factor Cross Section Btu hr ft F Btu hr ft F Head 4 7955 0 8445 3 5527 0 6257 Jamb 4 8084 0 8468 3 5455 0 6244 The figures on the following pages show the THERM cross sections and U factor results for this window THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 9 37 9 4 Problem 3 Flush Mount Skylight 9 SAMPLE PROBLEMS Head ESSE xi Skylight Head Modeling Assumptions Cross Section Type Head Gravity Arrow Down Glazing System Down File Rotation 70 Clockwise BC NFRC 100 2010 Exterior Radiation Model Blackbody U Factor Surface tag SHGC Exterior BC NFRC 100 2010 Exterior Radiation Model Blackbody U Factor Surface tag None BC Adiabatic U Factor Surface tag None BC 3 mm Generic U factor BC Adiabatic In
19. THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 104 8 SPECIAL CASES 8 10 Garage Rolling Doors entry door section for the principles of modeling embossed or raised panels which can then be applied to sectional doors The boundary condition details and other modeling assumptions used on the simulation models for door components are discussed in the following sections 8 10 1 1 Top Rail Model A nominal 2x4 wood block is used in the Top Rail Model as shown in the figure below The torsion spring assembly and any non continuous hardware shall not be included in this model The boundary condition BC type and U factor tags used in the model are illustrated in the figure below THERM File Properties Cross Section Type Head Gravity Arrow Down BC Adiabatic U factor tag None BC Interior lt frame type gt convection only Radiation Model AutoEnclosure U factor tag Frame Model the greater of 63 5 mm 2 5 or into 25 4 mm 1 of core material consistency from top edge of wood framing member BC NFRC 100 2010 Exterior U factor tag SHGC Exterior gt td BC Adiabatic U factor tag None Figure 8 98 Top Rail Model THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 105 8 SPECIAL CASES 8 10 Garage Rolling Doors 8 10 1 2 Bottom Rail Model A nominal 2 x 6 wood block is used in the bottom rail model of the garage door Refer to the figure below for the b
20. Thickness Hew wima Wee E mm mm 18 Stormwindow sill thm Therm Sill 0 439 1 915 NA TaB 69 0 0 452 1 930 NA Update aleme Source Type Copy Delete Advanced 3 records found Import Export Report Print For Help press F1 El Mode NFRC I MUM SCRL 4 Figure 8 55 Import the storm window THERM files Inthe WINDOW Window Library construct the storm window from the THERM files and the glazing system previously defined and calculate the total product values ss Window Library C Program Files LBNL WINDOW63 StormWindow mdb File Edit Libraries Record Tools View Help Cee SBOE SB hdr nla eN OHZ O x A List Cale F9 Hi New oO 3 z Delete Save Report ill Dividers Display mode Normal 4 For Help press F1 p s Name StormWindow Mode NFR Type Fixed picture 7 gt Width 1200 mm Height 1500 mm Area 1 800 m2 Tit 90 Environmental Conditions NFAC 100 2010 Total Window Results Click on a component to display characteristics below U tactor 7 W m2 K Frame aha Detail Name Stormwindow sill thm gt gt a i ID 18 Uedge 1 915 W m2 K CR a Detail Source 2 Edge area 0 063 m2 Ufactor 0 439 W m2 K PFD 69 0 Area 0 078 m2 Abs 0 300 oil Mode NFRC si Mum SCRL 4 Figure 8 56 Storm window created in the Window Library to obtain total product results THERM6 3 WINDOW6
21. modeled at 1 5 Clear Air Low E 0 6435 0 5771 0 5143 THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 9 13 9 2 Problem 1 Vinyl Fixed Window 9 SAMPLE PROBLEMS 9 2 7 Drawings Vinyl Fixed Window The following pages contain detailed drawings for this window Head Sill and Jamb 1 000 0 125 SEN e 0 482 0 143 0 625 Figure 9 11 Dimensioned drawing for the frame and stop 9 14 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 9 SAMPLE PROBLEMS 9 2 Problem 1 Vinyl Fixed Window Spacer Figure 9 12 Dimensioned drawing for the spacer Divider R0 0310 0 0310 0 9380 1 0000 0 2880 0 3500 Figure 9 13 Dimensioned drawing for the divider THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 9 15 9 3 Problem 2 Aluminum Horizontal Slider Window 9 SAMPLE PROBLEMS 9 3 Problem 2 Aluminum Horizontal Slider Window For this aluminum horizontal slider window example calculate the total product U factor SHGC VT and the specialty products table 9 3 1 Description Window Type Overall Size Frame Material Spacer type Weather Strip Cross Sections Dividers Glazing System Spacer Type Glazing Method Dividers Cross Sections 9 16 Horizontal Slider Width 1500mm Height 1200mm Aluminum painted white Thermal breaks as indicated in the drawing assembly The manufacturer indicated that the de bridge width is 0 250 for all the cross sections Thermal bre
22. rise T g r kS i spacing 7 y ks E tilt angle f F blind thickness Figure 8 150 Venetian blind geometry definition e Blind thickness This value is not editable and shows the width of the blind assembly based on the slat tilt In this Open case the blind thickness will equal the slat width At any other slat angle this value will be less than the slat width e Rise this value defines the curve of the slat and is defined in the CGDB for each Venetian blind product It can be changed if it does not represent the slat curvature being modeled this would be necessary if the slat width was changed for example 2 Shade Material Library When a Shading Layer record is imported from the CGDB the Shad e Material is automatically imported and therefore it is not necessary to add or change records in the Shade Material Library However you may need to reference existing records in the Shade Material Library if you are defining a new Shading Layer record for example to define a differen slat geometry for a product Shade Maternal Library C Users Public LBN Liw IN DOW EWE enetian mdb ID Hame ProductName Manufacturer Source 31107 White Venetian Blind Slat white tet White Venetian Blind Slat Pella CODE 31108 White Venetian Blind Slat white tet White Venetian Blind Slat Pella CODE 31109 White Venetian Blind Slat white tet White Venetian Blind Slat Fella CODE 31110 White Venetian Blind Slat white
23. 15 05 mm Set Glazing System system from the WINDOW library i s D Spacer height 19 05 mrn a Edge of Glass Dimension 63 5 mm Sight line to bottom of x Glazing System Ucenter 2 73 1 ea NFRC Che Thickness f 6 796 mm Glazing system height 150 mm glass and Spacer A height Divider height i Edge of Glass Dimension 63 5 mm 2 5 Site line to shade edge 0 EE Use nominal glass thickness 7 Glazing system height Shading layers None Use CR Model for Window Glazing Systems 150 mm 6 0 Close Gap Properties Exterior Boundary WINDOW Glazing System Library Defaut Custom Gap 1 Condition NFRC 100 C Program Files LBNL wINDOWE3 Window 6 Database Keff 0 066900 Ww eB 2010 Exterior width 12 mam 2 Interior Boundary Spacer Condition Use I Draw spacer convection plus Single spacer for multiple glazings enclosure radiation Material Fiberglass FE Resin Default Boundary Conditions Ixy 7 3 32 7 idx dy 242 7 217 3 len 325 8 Step 10 0 mm Provides access to WINDOW Glazing System Libraries f Use U factor values f Use SHGC values Interior Boundary Condition Use convection plus enclosure radiation Esterior Boundary Condition Use existing BC from library select below NFRC 100 2010 Exterior Figure 8 24 Import the first glazing system THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 23 8 SPECIAL CASES 8 3 Di
24. Adding an Applied Film to a Laminate In the same manner as adding an applied film to either a coated or an uncoated layer a film can be applied to a laminate This laminate can already exist in the IGDB or can be a laminate constructed using the NFRC Laminate Procedure The laminate is treated as a glass layer in the Glazing System tab and the applied film is then added to that layer 8 12 4 4 Change a Film To change the film applied to an applied film layer Select the applied film layer by clicking on the appropriate layer button Choose the menu option Edit Change Add Film The Change Glazing dialog box will appear The film name box is highlighted in blue click on it to select an applied film from the database you must select an Applied Film layer not a Film layer You must choose a film that is on the Approved Applied Films list The new film will replace the current film this is indicated in the Apply Film to section of the dialog box You will be prompted to enter a new name for the glazing Use the naming convention specified in the beginning of this document i e NFRC IDs for both the glazing layer and the applied film If you want to keep the new layer save it to the user database see Saving Layers to the User Database THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 139 8 SPECIAL CASES 8 12 Creating an Applied Film Layer in Optics for NFRC Certification 8 12 4
25. Autoenclosure one set for cross sections at a 90 tilt and another set for cross sections at a 20 tilt Interior Aluminum Frame Convection only Interior Thermally Broken Frame Convection only Interior Thermally Improved Frame Convection only Interior Wood Vinyl Frame Convection only Interior 20 tilt Aluminum Frame Convection only Interior 0 tilt Thermally Broken Frame Convection only Interior 20 tilt Thermally Improved Frame Convection only Interior 20 tilt Wood Vinyl Frame Convection only If there are frame materials that fall into more than one category a single boundary condition must be applied to the entire interior surface of a given frame section even if it contains different material components i e vinyl sash and aluminum frame The surface condition applied shall be the component with the greatest interior exposed area of that section For steel skin door boundary conditions see Section 8 7 Doors 6 28 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 6 MODELING FRAME AND EDGE HEAT TRANSFER WITH THERM 6 5 Defining Boundary Conditions Exterior The NFRC 100 2010 Exterior exterior boundary condition is used for all exterior surfaces including the glazing system and assumes that the surface is exposed to a 5 5 m sec 12 3 mph air velocity which corresponds to a convective film coefficient of 26 W m C 4 58 Btu h ft F Adiabatic The adiabatic boundary conditi
26. BC Interior lt frame type gt Convection only Radiation Model AutoEnclosure U factor tag None BC Interior lt frame type gt Convection only Radiation Model AutoEnclosure U factor tag Frame BC NFRC 100 2010 Exterior Radiation Model Blackbody U factor tag SHGC Exterior BC lt glazing system gt U factor Inside Film Radiation Model AutoEnclosure U factor tag Edge BC NFRC 100 2010 Exterior Radiation Model Blackbody U factor tag None BC lt glazing system gt U factor Inside Film Radiation Model AutoEnclosure U factor tag None Figure 8 96 Head Boundary Conditions head_boundary thm THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 101 8 SPECIAL CASES 8 9 Site Built fenestration products Curtain Walls Window Walls and Sloped Glazing For the Sill Use the drawing for the intermediate horizontal In Therm File Properties File Properties set the Cross Section Type to Sill Assign the Boundary Conditions as follows Interior Frame For the interior frame from the midpoint to the top sightline set the Boundary Condition to lt frame type gt Interior Convection Only and the U factor Surface tag to Frame For the interior frame from midpoint to the bottom sightline set the Boundary Condition to lt frame type gt Interior Convection Only and the U factor Surface tag to None Interior Glazing Set the Boundary Conditions for each
27. Default Boundary Conditions i Use U factor values Use SHGC values Exterior Boundary Condition Interior Boundary Condition use existing BC from library select below Use convection plus enclosure radiation NFRC 100 2010 Exterior v 4 b x y 102 2 173 0 idx dy 255 3 43 0 len 258 9 Step 10 0 mm A Ready Divider NM 4 Figure 8 35 Import the second glazing system as an additional glazing system facing down THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 34 8 SPECIAL CASES 8 3 Dividers 5 Add the spacers sealants desiccants and frame cavities as appropriate THERM 6 3 TrueDividedLite THM 7 loj x E File Edit View Draw Libraries Options Calculation Window Help la x DWBL s a irage peU OOS O Draw the spacers desiccants sealants and frame cavities as needed ae of x y 411 5 92 7 dx dy 661 5 1167 4 len 1341 8 Step 10 0 mm A Ready Divider NM 4 Figure 8 36 Draw the polygons to represent the divider THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 35 8 SPECIAL CASES 8 3 Dividers 6 Define the boundary conditions using the AutoEnclosure choice for the Radiation Model BC Adiabatic U factor tag None 4 BC lt glazing system gt U factor Inside Film Radiation Model AutoEnclosure U factor tag None BC NFRC 100 2010 Exterior U factor tag None BC lt glazing system gt U factor Inside Film Radiation Model AutoEn
28. Dright Dleft to the appropriate values for the venetian blind geometry THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 181 8 SPECIAL CASES 8 14 Venetian Blinds Between Glass Integral Glazing System Library ID H 25 Mame Lowe DblGlz Int B Closed H Layers 3 4 Tilt 90 IG Height 1000 01 mm Environmental on Conditions FRO 100 2070 IG wridth 1000 00 mm Comment Overall thickness 45 056 mm Mode ID Name Mode Thick Flip Tir E E2 Cond Dtop rom gt D bot mm right mm Cleft mrm Glass 1 9801 CLEARS LOF 30 O 0000 0840 0 840 1 000 1 Alir 254 O 3000 Slim white WB Closed 05 C 0o00 0 900 0 900 160 000 0 0 1 Alr 10 2 O 9921 LO W E_3 LOF 30 I 0000 0156 0840 1 000 Set values for Dtop Dbot Dleft Dright based on the geometry of the blind product Ufactor Rel Ht Gain Gap 1 Fett Gap 2 Felt Wonk Wiima Wonk wim 7 i if T Figure 8 169 Define a Dtop Dbot Dleft and Dright in the Glazing System Library THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 182 8 SPECIAL CASES 8 14 Venetian Blinds Between Glass Integral In THERM 1 Frame Geometry Draw the frame geometry including Head Sill Jamb and Meeting Rail if appropriate 2 Glazing System Import the glazing system defined with the venetian blind horizontal slats into the frame geometry For this example the Head cross section the following settings were used in the Insert Glazing System di
29. Frame fE 9232 z j TE aE 0 Projected in Glass Plane SHGC Exterior r 2563 39 0 fro 244 Projected in Glass Plane Edge E a03 39 0 63 5 a Projected in Glass Plane E t Eror Energy Norm 5 52 por Figure 9 20 THERM cross section and U factor results for Head Fixed Cross Section THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 9 25 9 3 Problem 2 Aluminum Horizontal Slider Window 9 SAMPLE PROBLEMS Meeting Rail BC Adiabatic U factor tag None Cross Section Type Vertical Meeting Rail Gravity Vector Into the Screen Gravity Yector led BC 3 mm CIG U factor Inside Film Radiation Model AutoEnclosure U factor tag None BC NFRC 100 2010 Exterior Radiation Model Blackbody U factor tag None BC 3 mm CIG U factor Inside Film Radiation Model AutoEnclosure U factor tag Edge BC Interior Thermally Broken Frame convection only Radiation Model AutoEnclosure U factor taq Frame BC NFRC 100 2010 Exterior Radiation Model Blackbody U factor tag SHGC Exterior BC 3 mm CIG U factor Inside Film Radiation Model AutoEnclosure U factor tag Edge BC NFRC 100 2010 Exterior Radiation Model Blackbody U factor tag None BC 3 mm CIG U factor Inside Film Radiation Model AutoEnclosure U factor tag None BC Adiabatic U factor tag None Ix U factor delta T Length Wt rin K Rotation C mm SHGC Exterior a J24 29 0 53 5427 30 0
30. Places Save as type User database mdb Cancel Figure 8 115 Specify the name of the new user database as well as the location where it will be stored THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 125 8 SPECIAL CASES 8 11 Creating a Laminate in Optics for NFRC Set the default user database to the newly created database from Tool Options arr lig File locations x Database locations Default folders Other preferences Main database GOB C Program Filess LBNLSLENL Shared User database Default 170 folder Standards Wavelengthsets folder 4 x cme E Figure 8 116 Define the location for the User Database from the Tool Options menu setting the User database field You can save a layer to the user database if it has a different filename to any layer currently in the user database or in the IGDB If you save a layer that has components such as a coated layer that has a substrate or a laminate which has component layers the component layers will be saved to the user database at the same time unless they already exist in the IGDB or user database This allows you to load and edit those layers at a later time If you want to save an unmodified layer from the IGDB to the user database you must change its filename first To save a layer to the user database Select the layer or system to save by clicking on a layer button Click the Save button on the toolbar or
31. SPECIAL CASES 8 10 Garage Rolling Doors 8 10 1 5 Edge of Lite Model The procedure for modeling edge of lite edge of glazing properties is the same procedure as for entry doors See the entry door procedure in this manual for detailed instructions for modeling these cross sections Below is a sample THERM cross section for the Door Lite Sill See Section 9 5 4 for the complete example for Entry Doors BC Adiabatic U Factor Surface tag None Gravity eckorse 4 BC lt glazing system gt U factor Inside Film Radiation Model AutoEnclosure U Factor Surface tag None r Modeling Assumptions Cross Section Sill Gravity Arrow Down BC lt glazing system gt U factor Inside Film BC NFRC 100 2010 Exterior Radiation Model AutoEnclosure Radiation Model Blackbody U Factor Surface tag Edge U Factor Surface tag None BC NFRC 100 2010 Exterior Radiation Model Blackbody U Factor Surface tag SHGC Exterior BC Interior lt frame type gt convection only Radiation Model AutoEnclosure U Factor Surface tag Frame BC Adiabatic U Factor Surface tag None Figure 8 102 Edge of Lite model for the garage door lite THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 110 8 SPECIAL CASES 8 10 Garage Rolling Doors 8 10 2 Rolling Door The overall product U factor is calculated based on area weighted average of various component s U factor The components used for area wei
32. The figure below shows another example of linking cavities based on whether the throat connecting the cavity to the glazing system cavity is less than 5 mm Figure 6 19 Example of a model where the cavities are not linked to the glazing system cavity but are instead modeled as frame cavities Figure 6 20 Example of a model where the cavities are not linked to the glazing system cavity but are instead modeled as frame cavities Frame Cavity NFRC 100 6 22 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 6 MODELING FRAME AND EDGE HEAT TRANSFER WITH THERM 6 4 Importing Glazing Systems Unsealed storm panel ae Sealed IG so 5 mm rule for 5 mm rule for linking iti i linking cavities is NOT T EE applied to the cavities J around the spacer Keff 0 232 Throat of this cavity is lt 5 mm so it is modeled as a frame cavity and not linked to the glazing system cavity B Keff 0 508 Glazing Syster Info x Glazing MomlinlG Lowe air Number of Glazings 3 Cancel U Factor 1 104 wal Arie K a Nominal Thickness i 31 251 rim Options CR Cavity Height SN mm Update Source CANFRE backup TIPC Sim Manual stul Layer properties Layer 1 ID zom Type Glass Name Ch306 OOOO Thickness 3000 mm nominal E missiwites Front 0 840 Back 0 840 lee Gas properties Cr Jame Air keff 0 508 ene ckness 106 629 mm I Shading properties Exterior shade Interior shade Ernisg
33. frame cavity and not linked to the glazing system cavity Glazing System Info x Glazing Momi inl Lowe air Inf Number of Glazing 3B mance U Factor 1 104 Wiemo K e Nominal Thickness haamo mm Options CR Cavity Height 275 008 ran Update Source CANFRE backup TIFC Sim Manual stul Laver properties Laserji ID jor Type Glass Keff 0 508 Name ee Thickness 3000 mm nominal Emissivites Front 0 840 Back 0 840 Keff 0 508 THekness 106 629 FAN e aaa Exterior shade Interior shade Emisfivity modifier MA Ba Unsealed storm panel Sealed IG so 5 Conv ction modifier MAA MA 5 mm rule for linking mm rule for linking cavities applies cavities is NOT applied to the cavities around the APA Link the cavity between the storm panel and the primary sash which has a throat of 25mm where it connects to the bottom glazing cavity to the glazing system cavity with the highest Keff ie the bottom cavity with a Keff 0 508 Figure 8 52 Link the cavity between the storm panel and the primary sash which is gt 5 mm to the glazing system with the highest Keff value THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 53 8 SPECIAL CASES 8 4 Storm Windows 8 4 4 Steps for Storm Window Condensation Resistance Calculation The Condensation Resistance model is only appropriate for horizontal frame components such as Head and
34. glass outside i inside In WINDOW 1 Shading Layer Library If the appropriate venetian blind product is not already in the Shading Layer Library import it from the Complex Glazing Database CGDB If the product is not in the CGDB the manufacturer will need to have the blind slat material measured and added to the CGDB before the product can be simulated The Shading Layer should be defined with the venetian blind slats in a horizontal position or as open as the blind geometry allows 2 Shade Material Library When the Shading Layer Library is imported from the CGDB WINDOW will also import the associated Shade Material record for that Shade Layer into the Shade Material Library In general this should be automatic and you should not have to manipulate the records in the Shade Material Library 3 Glazing System Library Define the glazing system with the venetian blind between two layers of glass In THERM 1 Frame Geometry Draw the frame geometry including Head Sill Jamb and Meeting Rail if appropriate 2 Glazing System Import the glazing system defined with the venetian blind horizontal slats into the frame geometry 3 Boundary Conditions For Integral Venetian Blinds set Shading System Modifier to None 4 Simulate the model save the results In WINDOW 1 Frame Library Import the THERM files into the Frame Library 2 Window Library Construct the window using the THERM files from the Frame
35. second polygon When using the multiple glazing calculation option THERM will automatically use the glazing system cavity properties for each glazing option for the linked polygon la x AB File Edit view Draw Libraries Options Calculation Window Help 8 x Doe el S Lt Set Material me Pe E u Frame Cavity NFRC 100 _ 7I Set Boundary Condition Material Library Shift F4 Boundary Condition Library Shift FS Gas Library Shift F6 Select Material Boundary Condition Glazing Systems F6 UFactor Names Remove Lint Step 2 Select the Libraries Create Link menu choice Step 1 Select the polygon labeled 1 in this example that is to be linked to another polygon Figure 8 75 Link the open spacer cavity to the glazing system cavity using the Library Create Link feature Step 3 The cursor will become an Eye Dropper Click the Eye Dropper in the polygon you want to link to in this example the large glazing cavity labeled 2 in this example The material properties of polygon 1 are now linked to the material properties of polygon 2 SO in this example the polygon below the glazing cavity 1 will have the same material properties as the qlazing cavity 2 THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 ofl 8 75 8 SPECIAL CASES 8 7 Spacers Another example of an open
36. strong intermediate piece The connecting piece of aluminum is then milled out leaving only the plastic to join the two halves of aluminum Functionally the resulting piece is cut mitered and assembled like a simple aluminum extrusion Thermally the plastic slows the heat flow between the inside and outside There are other manufacturing techniques for producing a thermal break such as crimped in place polymer strips but the thermal results are similar 2 4 3 Vinyl Frames Plastics are relative newcomers as fenestration product frame materials in North America Vinyl also known as polyvinyl chloride PVC is a versatile material with good insulating value The thermal performance of vinyl frames is roughly comparable to wood Large hollow chambers within the frame can allow unwanted heat transfer through convection currents Creating smaller cells within the frame reduces this convection exchange as does adding an insulating material Most manufacturers are conducting research and development to improve the insulating value of their vinyl fenestration product assemblies 2 4 4 Fiberglass and Engineered Thermoplastics In addition to vinyl fenestration products two other polymer based technologies have become available fiberglass and thermoplastics Frames can be made of glass fiber reinforced polyester or fiberglass which is pultruded into lineal forms and then assembled into fenestration products These frames are dimensionally stabl
37. suec Ost Glazing System Detail Mame LowE DbIGl Inf B Opern Non Fo gt gt ee In 24 Ucenter 1 933 w m2K CR N Deta Mayers 3 sc 0 790 Area 1 048 m2 SHGC 0 667 Edge area 0 278 rie Vie 0710 For Help press F1 Mode NFRC S NUM Figure 8 162 Define the window THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 176 8 SPECIAL CASES 8 14 Venetian Blinds Between Glass Integral 8 14 2 Closed Venetian Blind According to NFRC 100 and 200 dynamic glazing products must be rated in both their fully open and fully closed positions This section describes modeling a Venetian blind in it s closed position The modeling procedures presented here will apply to either a retractable or non retractable Venetian blind te Figure 8 163 A closed Venetian blind In WINDOW 1 Shading Layer Library If the appropriate venetian blind product is not already in the Shading Layer Library import it from the Complex Glazing Database CGDB If the product is not in the CGDB the manufacturer will need to have the blind slat material measured and added to the CGDB before the product can be simulated The Shading Layer should be defined with the venetian blind slats in a vertical position or as closed as the blind geometry allows 2 Shade Material Library When the Shading Layer Library is imported from the CGDB WINDOW will also import the associated Shade Material record for that Shade L
38. 0 20 inches and break up the larger frame cavity into smaller frame cavities ii Check the Nusselt number of the remaining large cavity a If the Nusselt number is lt 1 20 no further frame cavity division is necessary b If the Nusselt number is gt 1 20 go to iii iii Repeat step a for vertical diagonal throats The hatched area would be made into a separate frame cavity polygon The Nusselt number for this large cavity before After determining where to break up the cavity being broken up is gt 1 2 To implement the 5 delete those portions of the frame cavity by mm rule make a 5 mm polygon outside the deleting points and refill them with the same main cross section then move it around the cavity material frame cavity to find areas where there is a throat that is equal to or less than 5 mm 0 20 inches Figure 6 9 Breaking up frame cavities Breaking up cavities in this manner is not allowed They can only be broken up at throats Figure 6 10 Breaking up frame cavities in this manner is not allowed 6 12 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 6 MODELING FRAME AND EDGE HEAT TRANSFER WITH THERM 6 3 Draw the Cross Sections 6 3 7 Slightly Ventilated Exterior Cavities For NFRC simulations air cavities that are open to the exterior within a frame section such as the air cavity under the sash of a casement window that is vented to the exterior shall be modeled accor
39. 1 mm gt 1 5 modeled at 0 75 modeled at 1 5 Glazing Option No Dividers Clear Air Low E 0 5262 0 4750 0 4267 9 12 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 9 SAMPLE PROBLEMS 9 2 Problem 1 Vinyl Fixed Window VT Calculation Using Equation 4 2 from NFRC 200 Equation 4 2 from NFRC 200 is used to calculate the whole product VT from the VTo VTi and VT c VT VTo VIc VTi VTo Where VTC center of glazing VT calculated in the Glazing System Library of WINDOW for the best glazing option as Tvis VTO total product VT values for a center of glazing VT of 0 0 calculated in the Window Library of WINDOW for the best glazing option VILS total product VT values for a center of glazing VT of 1 0 calculated in the Window Library of WINDOW for the best glazing option VT total product VT calculated using Equation 4 2 The VT data from Table 9 5 is used with Equation 4 1 to determine total product VT as follows Without Dividers VT 0 0 0 7463 0 86224 0 0 0 6435 With Dividers lt 1 25 4mm modeled at 0 75 VT 0 0 0 7463 0 77328 0 0 0 5771 With Dividers gt 1 25 4mm modeled at 0 75 VT 0 0 0 7463 0 68917 0 0 0 5143 Table 9 7 Total product VT for the best glazing option Clear Air Low E Dividers Dividers lt 25 4 mm modeled gt 25 4 mm modeled at 19 5 mm lt 1 0 at 38 1 mm gt 1 5 Glazing Option No Dividers modeled at 0 75
40. 150 mm 6 0 glazing system height BC lt glazing system gt Inside Film Radiation Model AutoEnclosure U factor tag None BC NFRC 100 2010 Exterior U factor tag None BC lt glazing system gt Inside Film a Radiation Model AutoEnclosure f E Edge of U factor tag Edge glass BC Interior lt frame type gt convection only Radiation Model AutoEnclosure BC NFRC 100 2010 Exterior U factor taq Frame U factor tag SHGC Exterior BC Adiabatic U factor tag None Figure 8 50 Define the boundary conditions THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 51 8 SPECIAL CASES 8 4 Storm Windows 6 Simulate the problem and save the file 5 Foe amp 3 a5 Figure 8 51 Simulate the file THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 52 8 SPECIAL CASES 8 4 Storm Windows 8 4 3 Storm Window Meeting Rails In the case of a meeting rail with a storm window if the the space between the storm panel and the primary sash is gt 5 mm that space is linked to the glazing system cavity with the highest Keff effective conductivity value See Chapter 6 for the frame cavity glazing cavity linking rules for sealed and unsealed units Unsealed storm panel 5 mm rule for linking Sealed IG so 5 mm rule cavities applies for linking cavities is NOT f applied to the cavities around the spacer Keff 0 232 Throat of this cavity is lt 5 mm so it is modeled as a
41. 19 mm 0 75 Dividers 2 25 4 mm 1 modeled at 38 mm 1 50 7 6 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 7 TOTAL PRODUCT CALCULATIONS USING WINDOW 7 4 Overall Product U factor SHGC VT and CR Calculations WINDOW automatically calculates these values for all records in the Window Library using the U factor for the default divider as defined in NFRC 200 The values can be displayed by clicking on the Details button next to the whole product results for SHGC and VT as shown in the figure below FH W6 3 Window Library C Users Public LBNL WINDOW6 w6 mdb File Edit Libraries Record Tools View Help ca ki Be Z WNb Dl ael OH Ls Da Calc F9 Mame Picture Mode NFRC Type Fixed picture gt gt width 1200 mm pene Height 1500 mm save Area 1 800 m2 Report Tilt 90 Hew Copy ikter Environmental Conditions Dividers NFRE 100 2010 Dividers i Display mode Normal 4 Total Window Results 2 0103 vre K Click on a component to display characteristics below U factor SHGEc 0 6041 Detail SHGC and VT detail Detail No Generic Generic Dividers Dividers Dividers YT 0 6484 CAL 49 POD mm HA 15 05000 36 10000 SHGCO 0 00353 0 00647 0 00525 SHGCI 0 87235 0 792206 0 71025 WTO Cfick on the Detail button next to SHGC and ee eee eee VT to get the SHGC 0 amp 1 and VT 0 amp 1 a 08754
42. 26 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 6 MODELING FRAME AND EDGE HEAT TRANSFER WITH THERM Emissivity 1 0 Side Open Boundary conditions are drawn inside the glazing system cavity when the CR calculation is turned on Emissivity emissivity of adjacent material Side Adiabatic 6 5 Defining Boundary Conditions Emissivity glass layer emissivity Side Left Emissivity glass layer emissivity Side Right Figure 6 24 Modeling the profile with the CR model turned on THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 6 27 6 5 Defining Boundary Conditions 6 MODELING FRAME AND EDGE HEAT TRANSFER WITH THERM 6 5 Defining Boundary Conditions Chapter 6 of the THERM User s Manual contains a detailed explanation of how to define boundary conditions in a model The information found in this manual is supplemental to that discussion 6 5 1 Overview Boundary conditions must be defined for all the surfaces on the perimeter of the models as well as at the surfaces adjacent to the radiation enclosure These boundary conditions define the temperatures and film coefficients for each element of the perimeter Different boundary conditions are defined for the surfaces on the interior and the exterior of the cross section Surfaces which are assumed to have no heat transfer are assigned Adiabatic boundary conditions There are three main categories of boundary conditions Interior An interior
43. 8564 75 Air 5 2 Argon 95 Mix i 0 016704 0 000021 5393 729614 1 757349 Air 12 Argon 222 Krypton B64 Mix i 0 011450 0 000023 324 703613 3 014009 Air 54 7 krypton 352 Mix i 0 005151 0 000023 261 636536 3 615515 Air 1022 7 Argon 90 Mix i 0 017063 0 000021 558 033142 1 732065 8 records found Import Export Report Print Figure 5 10 WINDOW Gas Library 5 10 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 5 MODELING CENTER OF GLAZING WITH WINDOW 5 4 Solar Heat Gain Coefficient and Visible Transmittance 5 3 4 Laminated Glass Applied Films Section 8 describes the procedures for creating laminated glass layers and applied films using Optics and importing the results into the WINDOW Glass Library 5 4 Solar Heat Gain Coefficient and Visible Transmittance The document NFRC 200 Procedure for Determining Fenestration Product Solar heat Gain Coefficients at Normal Incidence contains the rules and definitions for calculating the Solar Heat Gain Coefficient and Visible Transmittance for products Consult NFRC 200 to determine how to group products for these calculations as well as algorithm documentation In WINDOW the center of glazing Solar Heat Gain Coefficient GHGC and Visible Transmittance VT are automatically calculated in the Glazing System Library in the Center of Glass Results tab as shown in the figure below In addition these values are calculated for the whole product and for the NFR
44. Adiabatic U factor tag None U factor delta T Length Wwe K mm Rotation E SHGC Exterior E 2433 E 57 6251 fao Projected in Glass Plane Frame 5 8804 E 57 56252 30 0 Projected in Glass Plane Edge 21 an4 E E35 30 0 Projected in Glass Plane 5 E t Error Energy Norm 0 03 __ Export e Figure 9 15 THERM cross section and U factor results for sill vent cross section x 9 20 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 9 SAMPLE PROBLEMS 9 3 Problem 2 Aluminum Horizontal Slider Window Sill Fixed BC Adiabatic Cross Section Type Sill U factor tag None Gravity Vector Down 4 U factor tag SHGC Exterior p t BC Adiabatic _ fF U factor tag None Factors ee xi U factor delta T Length Wi me F mm Rotation C Frame B 8507 39 0 57 3204 30 0 Projected in Glass Plane 33 0 BC 3 mm CIG U factor Inside Film Radiation Model AutoEnclosure U factor tag None BC NFRC 100 2010 Exterior Radiation Model Blackbody U factor tag None BC NFRC 100 2010 Exterior Radiation Model Blackbody e BC 3 mm CIG U factor Inside Film Radiation Model AutoEnclosure U factor tag Edge BC Interior Aluminum Frame convection only Radiation Model AutoEnclosure U factor taq Frame SHGC Exterior 2 081 z E 57 3204 90 0 Projected in Glass Plane Edge 2 0555 63 5 30 0 Projected in Glass Plane Eror Energ
45. Air Emissivities The default emissivities that are included in this frame cavity material are essentially irrelevant because THERM will recalculate and override them during the simulation of the cross section However when either the Frame Cavity NFRC 100 or the Frame Cavity Slightly Ventilated NFRC 100 the frame cavity surfaces will be outlined in red Double clicking on one of these red surface segments will display a dialog box that can be edited This allows the emissivity values assigned by the program to be overridden The edited values will then be what the program uses for the simulation THERM also makes the following assumptions about the frame cavity Default frame cavity height 1 meter Gravity vector based on Cross Section Type see Section 6 3 2 Cross Section Type and Section 6 3 3 Cross Section Orientation 6 8 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 6 MODELING FRAME AND EDGE HEAT TRANSFER WITH THERM 6 3 Draw the Cross Sections If the frame cavity model is set to ISO 15099 which it is for Frame Cavity NFRC 100the emissivities temperatures and heat flow direction will be automatically calculated by the program during simulation Therefore the default values that appear for individual frame cavities before the simulation do not need to be edited These automatic calculations are computed as follows Heat Flow Direction The calculated heat flow direction will depend on
46. Although in general it is best to rotate and flip cross sections before the glazing systems are imported and boundary conditions are defined the exception is skylights which are modeled at a tilt In that case import the glazing system in a vertical orientation define the boundary conditions and then rotate the entire cross section Glazing Orientation Up Locator Lower left corner Glazing Orientation Down we Locator Upper left corner Figure 6 15 The Locator position when importing glazing systems in different orientations 6 16 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 6 MODELING FRAME AND EDGE HEAT TRANSFER WITH THERM 6 4 2 Inserting Glazing Systems 6 4 Importing Glazing Systems The THERM User s Manual contains a detailed description about how to insert glazing systems into a THERM file for U factor and Condensation Resistance calculations The figure below is a brief overview of the steps THERM 6 3 Untitled 2 E File Edit View Draw Libraries Options Calculation Window Help Seb Material D Hal Ell Set Boundary Gondition Material Library Boundary Condition Library gas Library Select Material Boundary Gondition Glazing Systems UFactor Mames Greate Link Remove Link Step 2 Select the Glazing System from a WINDOW glazing system library same thickness Insert Glazing System Orientation Up hi Glazing system width fis 0532 mm CH cavity height foo mm Sig
47. AutoEnclosure U factor Tag Edge BC Interior lt frame type gt Convection only Radiation Model AutoEnclosure U factor Tag Frame BC NFRC 100 2010 Exterior U factor Tag SHGC Exterior i Sightline BC lt glazing system name gt U factor Inside Film Radiation Model AutoEnclosure U factor Tag Edge BC NFRC 100 2010 Exterior U factor Tag None BC lt glazing system name gt U factor Inside Film Radiation Model AutoEnclosure U factor Tag None BC Adiabatic U factor Tag None Figure 8 8 Define the Boundary Conditions for the meeting rail THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 7 8 SPECIAL CASES 8 2 Meeting Rails 8 Run the simulation by pressing the Calc toolbar button clicking on the Calculation Calculation menu 9 choice or pressing the F9 key The U factor results are calculated for the Frame and Edge U factor tags as shown in the figure below U factor delta T Length Wi me k mm Rotation E SHGC Exterior 7 3057 29 0 pa 5427 aoo Projected in Glass Plane Frame 7 0598 39 0 49 301 F faon Projected in Glass Plane Edge 2 0251 39 0 fi 30 177 ao 0 Projected in Glass Flane z E t Error Energy Morr 30t Em B x Figure 8 9 Calculate the results Import the THERM file into the WINDOW Frame Library 8 2 3 Steps for Meeting Rail Condensation Resistance Calculation The Condensation Resistance model is only appropriate for horizo
48. Avoid g ating duplicate records in export database by searching for ntical records coc Delete ud Find mm 4 z Suspe Import button This will open the 4 4 H Open i ertic Advanced Import dialog box Look in J WINDOWS h ey E 7 records found Step 2 Set the Format to Name Date modified Type Sim dJi Debu 5 20 2013 2 45PM File folder c di BSDFs 5 14 2013 1 53 PM File folder Seman Step 3 Select the THERM files de Samples 4 22 2013 5 17PM File folder to import Ji XML 11 15 20126 34PM_ File folder Print F m File name Step 4 Specify the record number or use Files of type Them files thm Cancel the program default number which is an increment from the last record Oe Daannesead ant ay C 4Users Public LBNL WINDOWED vider THM Cancel ID for new record E lazing Prd Abs Divider Library C SU sers Public LBNL Y M Detailed View Update ID Mame epee Color ae Overarite existing records a a k 2 Butyl Divided Ta ma 1159 om B 3 Wood Divided ASHAAE Suspende N A N A Class3 N A 16 9 0 90 4 insu Divided ASHRAE Suspende N A HA Class4 ALAA las 0 90 Lo 5 Alum Suspended ASHRAE Suspende N A N A Class5 N A 16 0 0 30 a 6 Viryl Suspended ASHAAE NAA H A HA Class H A 16 0 0 30 7 divider 3rmm THM Therm Yerticald 2 010 Tie AAA 25 4 25 4 0 30 A Ana E Divider THM Them WVeticalD 2248 1 890 NA 54 191 oa P 8 records fo
49. File Edit Database wiew Tools Graph Help DO ca bel AE IEE Main Database IGDB Glazing System Laminate Add Glazing Add Interlayer Add Embedded Coating Edit Laminate View All Schematic Warnings Layer 1 2 H3 arin lt Dutside Filename CLEAR BLUGR Optiw3 CalcLa solar T 0834 0 859 0 904 0 703 solar AF noz5 aooo oos foose solar Ab 075 000 0 081 0 067 photopic T 0 899 D834 o2 Ora photopic AF oos3 ooo oo ooa 2 9 mm photopic Ab oosa ooon foo ooa E mit aaa 000 ea nea Coating Applied Film Emib foaso o o00 nea aa J CalcLamusr 2 a ywS_NFRC_2003 FRY IGDE version 14 3 Spectral Properties Filename CalcLam usr CalcLam usr solar T 0 703 solar Af 0 066 solar Ab 0 067 photopic T 0 747 photopic Af 0 071 photopic Ab 0 071 EmitF 0 840 Emitg 0 840 pS a IUU Wavelength microns o Transmission Fefectance Font Reflectance back When the Lamin Button above is selected the graph below displays the properties of the entire laminate construction Figure 8 112 Click on the Lamin button to view the optical properties of the entire laminate structure To view a schematic diagram of the laminate select the Schematic tab in the upper right part of the screen THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 122 8 SPECIAL CASES 8 11 Creating a Laminate in Optics for NFRC To view the spectral data in a table choose menu option View Spe
50. Glazing System Library List Cale F3 ID 2 Mame Skylight DoubleG New Layers 2 F Tilt J 20 IG Height 1000 mm Copy Envronmenta ERC 100 2010 l IG Width 1000 mm Delete Comment oo 1 Fa Overall thickness 16 900 mm Mode jt ID Mame Mode Thick Flip Tol Aeoll Asol Twiss Avis Ayvis2 Tir E E2 Cond Glass 1 ee 102 CLEAR_3 DAT 30 C 0834 0075 0 075 0899 0083 0 083 0000 O840 0 840 1 000 Gapl H 1 ir 10 9 C Glass 2 e 102 CLEAR_3 DAT 30 joss 0 075 0 075 0 899 0083 0 083 0 000 0 840 0 840 1 000 oren Save Report kte Center of Glass Results Temperature Data Optical Data Angular Data Color Properties factor SIE SHG Rel Ht Gain Tis Keff wi fra2 F wi fre wt rack 3 22992 0 87935 0 76503 576 0 0 81427 0 0729 El For Help press F1 Mode NFRC si Num 2 Figure 9 34 WINDOW Glazing System Library for the skylight The results for the center of glazing U factor are shown in the following table Table 9 17 Center of glazing U factor results from WINDOW Glazing Options Center of glazing U Factor 17 mm 0 669 overall thickness BTU hr ft2 F This glazing system will be used in THERM to calculate the frame and edge of glazing U factors and also in WINDOW to calculate the overall product U factor 9 36 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 9 SAMPLE PROBLEMS 9 4 Problem 3 Flush Mount Skylight 9 4 4 Edge of glazing and Frame Modeling THERM
51. PC Program for Analyzing the Two Dimensional Heat Transfer Through Building Products LBL 37371 Rev 2 George P L Automatic Mesh Generation Application to Finite Element Methods John Wiley amp Sons Pepper P W and Heinrich J C 1992 The Finite Element Method Basic Concepts and Applications Hemisphere Publishing Corporation Washington Carmody J Selkowitz Arasteh D S Heschong L Residential Windows A Guide to New Technologies and Energy Performance Second Edition 2000 W W Norton amp Company Rohsenow W M Harnett J P and Ganic E N 1985 Handbook of Heat Transfer Fundamentals 2nd Edition McGraw Hill Shapiro A B 1986 TOPAZ2D A Two Dimensional Finite Element Code for Heat Transfer Analysis Electrostatic and Magnetostatic Problems Lawrence Livermore National Laboratory Rept UCID 20824 Shapiro A B 1990 TOPAZ2D Heat Transfer Code Users Manual and Thermal Property Data Base Lawrence Livermore National Laboratory Rept UCRL ID 104558 May 1990 Shapiro A B 1983 FACET A Radiation View Factor Computer Code for Axisymetric 2D Planar and 3D Geometries with Shadowing Lawrence Livermore National Laboratory Rept UCID 19887 Thermal Performance of Windows Doors and Shading Devices Detailed Calculations ISO FDIS 15099 ISO TC 163 THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 B 1 APPENDIX B REFERENCES Zhao Y Curcija D and Goss W P 1996 Condensation Re
52. Rel Ht Gain Kett Gap 1 Kett Gap 2 Kett Sat rete Vat rni K We rk Taf roi k FAI 0 1207 0 1732 0 0198 E Select Cancel Find ID 20 records found Producth ame Manufacturer Click on the Venetian C45 ISO 15099 appendix Y enetiar double arrow Venetian C90 ISO 15099 appendix Wenetiar to see the Venetian C90 ISO 15099 appendix Y enetiar Shading Venetian DO ISO 15099 appends V enetiar Layer Libra ry Venetian D45 150 15099 appendix VWenetiar list Venetian O90 ISO 15099 appendix VWernetiar White Frit Generic Fritted gl Clear Frit no pigment Generic Fritted gl Slim White VB Closed Slim White Venetian Blind Pella Wenetiar Slim White Open Slim White Venetian Blind Boog Viraspan TM Medium Gray Y S948 30 Viraspan TM Ceramic Frit Medium Gray 948 30 Coverage 9 VYiracon Fritted gl 5001 Simulated Sandblast 1086 70 Translucent Frit Simulated Sandblast V 1096 70 Coverage Viracon Fritted gl K002 Viraspan TM Medium Gray v 948 60 Viraspan TM Ceramic Frit Medium Gray 948 30 Coverage Viracon Figure 8 152 For the middle layer in the Glazing System Layer 2 select the venetian blind from the Shading System Library e Set Number of layers 3 e Set Layer 2 to Shade from pulldown arrow to the left in the first column e Set Dtop Dbot Dright Dleft to the appropriate values for the venetian blind geometry These distances are based on the distance between the top of the venetian blind incl
53. Software Approval Complex will automatically Frit coverage 70 0 rs i mn be imported into ID Hame Producth ame SOUICE Frit optical data the Glass Library 5 La la j a PEE Bi DES yecular Jo ee __ gogoo 1086S pecular bl Translucent Frit Simulated Sar CODE v1 01 Diffuse 60001 1086Dittuse Jbl l go001 1086Ditfusze lbl Translucent Frit Simulated Sar CODE v1 01 g0g002 9495 pecular Ibl Viraspan TM Ceramic Frit Med CODE v1 01 ggo02 46D use Ibl Viraspan TM Ceramic Frit Med COCE v1 01 Figure 8 190 The necessary records will be imported into the Glass Library for the frit layer THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 201 8 SPECIAL CASES 8 16 Complex Glazing Database CGDB 3 Shading Layer Library Venetian Blind Records Highlight one of the Venetian blind records and click on Detailed View to see the details of the Venetian blind definition The Detailed View will show the Blind Geometry which includes Effective Openness Fraction Slat Width Slat Spacing Tilt and Rise Effective Openness Fraction If the default values in the CGDB record are not what you want to model you can edit these values as needed to model the Venetian blind correctly In general for NFRC certification you are going to be modeling either Open or Closed blinds so the Effective Openness Fraction will be Retracted Open 1 0 e Closed 0 Shading Layer Library ID S002 Name 5lim white Open Product Hame Sl
54. Tag Frame BC lt glazing system name gt U factor Inside Film Radiation Model AutoEnclosure U factor Tag Frame pa BC lt glazing system name gt U factor Inside Film Radiation Model AutoEnclosure U factor Tag Edge BC lt glazing system name gt U factor Inside Film Radiation Model AutoEnclosure U factor Tag None BC Adiabatic U factor Tag None BC Adiabatic U factor Tag None BC NFRC 100 2001 Exterior U factor Tag SHGC Exterior BC NFRC 100 2001 Exterior U factor Tag None Figure 8 142 Define the boundary conditions for the cross section THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 156 8 SPECIAL CASES 8 14 Venetian Blinds Between Glass Integral 6 Calculate the results for this cross section 7 Complete the calculations for the other product cross sections Sill Jambs and Meeting Rails Stiles as appropriate 8 Import all the cross sections into the WINDOW Frame Library and calculate the total product U value SHGC and VT THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 157 8 SPECIAL CASES 8 14 Venetian Blinds Between Glass Integral 8 14 1 2 Fully Retracted Open Venetian Blind Between a Double Glazed System and a Third Glazing Layer The following figure shows the Head cross section for a venetian blind in the fully retracted position between a double glazed system with a third glazing layer such as but not lim
55. U factor depends on the thermal properties of the materials in the fenestration product assembly as well as the weather conditions such as the temperature differential between indoors and outside and wind speed NFRC has standardized the exterior conditions called environmental conditions for U factor calculations for product ratings using the following temperatures and wind speeds Wind Speed 5 5 m s 12 3 mph Indoor air temperature 21 C 70 F THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 3 3 3 3 Temperature Driven Heat Transfer 3 FENESTRATION HEAT TRANSFER BASICS Outdoor air temperature 18 C 0 F Skylights and roof fenestration products are simulated at a 20 degree slope from horizontal 3 3 4 1 Total Product U factor The U factor of a total fenestration assembly is a combination of the insulating values of the glazing assembly itself the edge effects that occur in the insulated glazing unit and the insulating value of the frame and sash 3 3 4 2 Center of Glazing U factor The U factor of the glazing portion of the fenestration unit is affected primarily by the total number of glazing layers the dimension separating the various layers of glazing the type of gas that fills the separation and the characteristics of coatings on the various surfaces The U factor for the glazing alone is referred to as the center of glass U factor 3 3 4 3 Edge Effects A U factor calculation assumes that heat flow
56. View of U factor settings THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 5 7 5 3 Glazing System Library Center of Glazing U factor 5 MODELING CENTER OF GLAZING WITH WINDOW Table 5 1 Environmental Conditions for NFRC Simulations for U factor calculations Outside Temperature OoF Sky Temperature Tsky QoF Use the NFRC 100 2010 Environmental Conditions Library in WINDOW for NFRC center of glazing simulations Environmental Conditions Library Environmental Conditions Library ID il ID i Name MFRC 100 2070 Name MFAC 100 2010 U factor Inside U factor Outside SHGC Inside SHG Outside U factor Inside U factor Outside SHGC Inside SHGC Outside Inside Air Temperature e400 Outside Air Temperature 32 0 C Direct Solar Radiation 783 0 W m Convection Convection Model A5HRAE NFAC Inside Model E5SHAAE NFARC Outside Convection Coef 15 000 wrm2 kK Outside Wind Speed 2 00 ms Wind Direction windward Radiation Radiation J ASHRAE NFRC ASHRAE NFRC Effective Room Temperature 240 C Effective Sky Temperature 32 0 C Effective Room E rissivity 1 000 Effective Sky E missivity 1 000 Figure 5 8 WINDOW Environmental Conditions Library Settings for SHGC Table 5 2 Environmental Conditions for NFRC Simulations for SHGC and VT calculations Variable Sl Units IP Units Sky Temperature TKY 5 8 June 2013 THERM6 3 WINDOWG6 3 NFRC Simulation Manual 5 MODELING CENTER OF GL
57. are used ina product by using the U factor temperatures for the dividers Draw the true geometry of the divider in the upper glazing system in the spacer area Depending on the fill of the glazing system assign the appropriate frame cavity material to the cavities between the glazing system and the divider as well the cavity inside the divider as follows e For air filled dividers Assign Frame Cavity NFRC 100 2010 material e For gas filled dividers Create a new material in the Material Library that is identical to the Frame Cavity NFRC 100 2010 material except that the gas used in the glazing system found in the Gas Library is referenced in the Gas Fill field Assign this new material to the cavities in the divider See the example below Assign Boundary Conditions Simulate the results Import the file into the WINDOW Divider Library Reference the Divider as appropriate from the Window Library when constructing the whole product THERM6 3 WINDOWG6 3 NFRC Simulation Manual June 2013 8 10 8 SPECIAL CASES 8 3 Dividers 8 3 1 2 Air Filled Glazing Systems The modeling steps for a divider with an air filled glazing system are explained in detail in the following pages In THERM 1 Set the Cross Section Type to Vertical Divider 2 Import the glazing system for the divider which is the same glazing system as the rest of the product with the following settings Orientation Up CR Cavit
58. as the gas fill material between the layers such as air or argon Shading systems as described in Section 8 of this manual can be modeled with glazing systems Detailed instructions about creating a glazing system can be found in the WINDOW 6 3 User s Manual A simple glazing system library entry is shown in Figure 5 3 When defining a glazing system the number of glass layers Lay the Tilt and the Environmental Conditions Env Cond must be specified For NFRC certification calculations the Environmental Conditions have restricted values as discussed in the next section Also the glass layers must be from the Glass Library using approved records from the International Glazing Database indicated by a value in the Mode field of the glass layer record as shown in Figure 5 3 Note to see the U factor value to four decimal places click on File Preferences menu choice and in the Options tab set the Display Precision field to 4 A w63 Glazing System Library C Users Public LBNL WINDOW6 w6 mdb File Edit Libraries Record Tools View Help iS b Bge H i Wd r gt wW Bae pi OF a NM Glazing System Library For NFRC certification calculations the Calc F9 ID 2 Name Double Clear Air New H Layers Aa Tilt 90 4 IG Height 1000 0 mm NFRC 100 2010 Environmental a ao Environmental Sr itinne NFRC 100 2010 IG Width 1000 00 mm Conditions Delete Comment choice must be Save Overall thickness 24 000 mm Mode 3 u
59. bet White Venetian Blind Slat Pella CODE white Venetian Blind Slat Pella CGDE 91112 Marne Venetian Blind Slat marine txt Manne Venetian Blind Slat Pella CODE 31113 Marine Venetian Blind Slat marine txt Marne Venetian Blind Slat Pella CODE 31114 Marne Venetian Blind Slat marine txt Marine Venetian Blind Slat Pella CODE 97115 BSOF Maternal Hescel Screens 52 3 Nysan CODE Figure 8 151 Shade Material Library records are automatically created when Shading Layers are imported from the CGDB THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 166 8 SPECIAL CASES 8 14 Venetian Blinds Between Glass Integral Glazing System Library Define the glazing system with the venetian blind between two layers of glass Glazing System Library ID 24 Name LowE DblGlz Int B Open Non Retract H Layers E Tilt 90 E Height 1000 01 mm Environmental Dn Conditions FRL 100 2010 IG width 1000 00 mm Comment Overall thickness 46 892 mm Mode ID Mame Mode Thick Flip Tal Roll Reole Twis Avil Awis Tir E E2 Cond 9801 CLEAR3 LOF 30 0837 0 075 0 075 0 899 0083 0 083 0o00 O840 0 840 1 000 Gapi 1 Air 271 9 LI Shade 2 FF 3002 Slm white Open 14 6 0 000 0 500 0 500 160 000 Set Layer 2 AF E T to Shade using the f 9921 LOW E 3 LOF 30 0652 0122 0112 0824 0115 0110 0000 O156 0 840 1 000 pulldown Ceyfer of Glass Results Temperature Data Optical Data Angular Data Color Properties
60. boundary condition is used for all interior surfaces and assumes that the surface is exposed to natural convection and the heat transfer coefficient used depends on the temperature of the surface which is a function of the material For Glazing Systems The interior glazing system boundary conditions should be set to the boundary condition that is associated with the glazing system imported from WINDOW WINDOW calculates the center of glazing surface temperatures and THERM uses these values to automatically calculate the edge of glazing boundary conditions for glazing systems imported from WINDOW At the time the glazing system is imported from WINDOW set the Interior Boundary Condition pulldown to Use Convection plus enclosure radiation which will cause the program to set the glazing system interior boundary condition Radiation Model to AutoEnclosure THERM will then model the cross section with the radiation enclosure feature which is required by NFRC for all simulations without the geometry of Radiation Enclosure being drawn The boundary condition is named lt filename gt lt glazing system name gt U factor Inside Film Double click on an interior boundary conditions to see its characteristics as shown in the figure below For Frame Elements Set all non glazing system interior boundary conditions according to the material from the following predefined boundary conditions which all have the Radiation Model set to
61. button which will import the selected records into the Glass Library THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 129 8 SPECIAL CASES 8 11 Creating a Laminate in Optics for NFRC ss Window Library C Program Files LBNL WINDOW63 w6 mdb File Edit Libraries Record Tools Yiew Help Cee see SlHpin gt wn GBlaehi OF 7 Glass Library C Program Files LBNL WINDOW63 w6 mdb Detailed View ID Name ProductName Manufacturer Source Model Color Thickness Tsol Asol Rsol2 Tvis Rvisl Rvis2 Tir emis emis mm 14701 Eurofloat4 EGS Eurofloat 4mm Euroglas GmbH IGDB v17 4 3800 0 850 0 077 0 077 0 904 0 083 0 083 0 000 0 840 0 840 14145 SSTSTNeutral5S0EF6 GTS Silverstar Sunstop T Glas Trosch AG IGDB v17 4 5800 0 455 0 158 0 090 0 506 0 153 0 122 0 000 0 756 0 840 Delete 14700 Eurofloat3 EGS Eurofloat 3mm Euroglas GmbH IGDB v17 4 2800 0 866 0 079 0 079 0 907 0 083 0 083 0 000 0 840 0 840 14701 Eurofloat4 EGS Eurofloat 4mm Euroglas GmbH IGDB v17 4 3 800 0 850 0 077 0 077 0 904 0 083 0 083 0 000 0 840 0 840 14702 EurofloatIO EGS Eurofloat 10mm Euroglas GmbH IGDB v17 4 9 800 0 764 0 071 0 071 0 886 0 081 0 081 0 000 0 840 0 840 14706 EurowhiteS EGS Eurowhite Smm Euroglas GmbH IGDB v17 4 4 800 0 895 0 083 0 083 0 910 0 087 0 087 0 000 0 840 0 840 14707 Eurowhites EGS Eurowhite 8mm Euroglas GmbH IGDB v17 4 7 800 0 984 0 082 0 082 0 908 0 087 0 087 0 000 0 840 0 840 ee 14708 Eurowhite6 EGS Eurowhite 6mm Euroglas GmbH
62. by THERM in this example it is 33 4315 mm Frame 18 6544 ha 33 4315 NA Pro a palge Eror Energy Mom Espot Step 2 lt The Length field will become editable Enter U Factors ii xj the correct length Step 3 U factor delta T Length Wi frng K C mm Rotatio THERM recalculates Edge e0 a ae uy the U factor based on the custom frame d Fae 39 8469 41 9 15 651 naa l ustom length length Step 1 Select Custom from the pulldown Error Energy Norm rel Export Figure 6 38 The Custom Frame Length feature allows the correct frame length to be entered 6 6 7 Importing Results into WINDOW Because the U factors and temperatures from individual THERM cross sections will be used for the whole product calculations in WINDOW it is necessary to import the THERM files with U factor and simulation temperature results into the WINDOW program This is explained in detail in the WINDOW User s Manual Section 4 7 3 Importing THERM Files The basic steps are u Create the THERM models calculate the results and save and close the files Open WINDOW and go to the Frame Library List View Click on the Import button select the Therm Files option from the pulldown then THERM files to import select multiple files using either Shift or Ctrl keys WINDOW will ask how to number the new Frame Library records either sequentially starting from the last existing record or overwriting existing r
63. calculate the boundary conditions for the glazing system to the Autoenclosure radiation model which does not require the Radiation Enclosure geometry to be drawn The nominal thickness feature turned on by checking the Use nominal glass thickness when importing a glazing system can be useful for multiple glazing options where THERM expects all the glazing system options to have identical thicknesses This feature is explained in more detail in the THERM User s Manual 6 4 3 Multiple Glazing Options THERM allows multiple glazing options to be associated with a glazing system This feature can be useful for simulations where many different glazing systems are to be modeled in the same frame cross section To use this feature follow these steps 1 6 18 Determine the frame cross sections to be modeled The glazing options for a frame cross section must be identical in their geometry including overall thickness cavity thickness spacer height and sight line dimension Therefore the first step is to determine the number of frame cross sections including dividers and meeting rails that must be defined in THERM for each set of glazing options Create and Simulate the Base Case File For each frame glazing option set create a THERM file with the complete frame cross section and one of the glazing options Create the boundary conditions for this model making sure to check the Use convection plus enclosure radiation wh
64. component of the product separately See ISO 15099 for detailed algorithm documentation All the transparent regions center of glazing edge of glazing and edge of divider have the same SHGC Once the SHGC of the opaque elements is determined the total SHGC is calculated as the area weighted average of the SGHC through the transparent and the opaque portions of the fenestration product as shown below SHGC l SHGG Ar SHGCa Aa SHGCe Ae SHG Cae Ade SHGC Ac 4 2 Apf Where SHGC Total product SHGC dimensionless Apt Projected fenestration product area m ft SHGC Frame SHGC dimensionless Af Frame area in m ft SHGCa Divider SHGC dimensionless Ad Divider area in m ft SHGC Edge of glazing SHGC dimensionless Ae Edge of glazing area in m ft SHGCae Edge of divider SHGC dimensionless Ade Edge of divider Area in m ft SHGC Center of glazing SHGC dimensionless Ac Center of glazing area m ft For NFRC rating purposes Section 4 7 of NFRC 200 shall be followed to obtain SHGC values 4 4 3 Visible Transmittance The whole product area weighted visible transmittance calculation is shown below VT VT Af VTa Aa VTe Ae VTae Ade VTc Ac 4 3 Apf Where VT Total product VT dimensionless Apf Projected fenestration product area m ft VT Frame VT dimensionless Af Frame area m ft VTa D
65. direction The Cross Section Type is set to Sill because the dominant direction of gravity is not vertical as itis with a normal jamb a The glazing system is oriented Up The gravity vector is set by hand to Right 2 Simulate the file Because the cross section is not rotated the projection in the U factor dialog box can be set to either Projected Y or Projected in Glass Plane both settings will result in the same answer Factors ee x U factor delta T Length Wi fim E E mrm Rotation Frame 4 5282 E 43 0002 j90 0 Projected in Glass Plane SHGC Exterior 51 595 so 48 5853 Projected in Glass Plane so 90 0 Edge 3 5455 63 5 faon Projected in Glass Plane Error Energy Norm F a02 Export Figure 8 68 The projection can be set to either Projected Y or Projected in Glass Plane both will result in the same answer THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 67 8 SPECIAL CASES 8 5 Skylights BC Adiabatic U factor tag None i 150 mm 6 inch BC lt glazing system name gt U factor Inside Film glazing Radiation Model AutoEnclosure system U factor tag None height BC NFRC 100 2010 Exterior U factor tag None 63 5 mm 2 5 inch Edge of glass BC lt glazing system name gt U factor Inside Film Radiation Model AutoEnclosure U factor tag Edge BC Interior 20 tilt lt fra
66. each cross section as needed A library of spacer models can be produced for each spacer type See the THERM User s Manual Section 3 5 Adding a Custom Spacer A sample spacer spacer thm is included on the THERM installation CD THERM Spacer thm Iof x ao File Edit View Draw Libraries Options Calculation Window Help x Dah e bo stiedre aged ule a ay 0 525 1 990 ide dy 0 136 0 004 len 0 136 Step 0 500 inches Ready NUM SS S Figure 8 74 Spacer thm sample file THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 74 8 SPECIAL CASES 8 7 Spacers 8 7 2 Linking Glazing Cavity properties imported from WINDOW for Open Spacers The properties of a glazing cavity can be linked to another polygon in order to properly model spacers that are open to the glazing system cavity Section 5 11 5 Linking Materials Properties of Polygons in the THERM User Manual explains this methodology in detail Follow the rules in Section 6 4 4 to determine whether the cavities in the open spacer cavity should be linked to the glazing system cavity To Link the properties of two materials follow these steps Select the polygon that is to linked to another polygon Select the Libraries Create Link menu choice The cursor will become an Eye Dropper Click the Eye Dropper cursor in the polygon to be linked to The material properties of the first polygon are not linked to the material properties of the
67. effect of further improving the overall U factor 2 6 9 2 Coating Types There are two basic types of Low E coatings sputtered and pyrolytic referring to the process by which they are made The best of each type of coating is colorless and optically clear Some coatings may have a slight hue or subtle reflective quality particularly when viewed in certain lighting conditions or at oblique angles A sputtered coating is multilayered typically three primary layers with at least one layer of metal and is deposited on glass or plastic film in a vacuum chamber The total thickness of a sputtered coating is only 1 10 000 of the thickness of a human hair Sputtered coatings often use a silver layer and must be protected from humidity and contact For this reason they are sometimes referred to as soft coats Since sputtering is a low temperature process these coatings can be deposited on flat sheets of glass or thin plastic films While sputtered coatings are not durable in themselves when placed into a sealed double or triple glazed assembly 2 12 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 2 FENESTRATION PRODUCTS 2 6 Improved Glazing Products they should last as long as the sealed glass unit Sputtered coatings typically have lower emittances than pyrolytic coatings They are available commercially with emittance ratings of e 0 10 to as low as e 0 02 e 0 20 means that 80 percent of the long wavelength radiant energy rece
68. ft F THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 85 8 SPECIAL CASES 8 8 Non Continuous Thermal Bridge Elements Step 2 Replace the strip of air aluminum air with new keff material of 15 078 W m K Thermal debridged Apply keff for each skip and slot row Keff 8 918 W m K air aluminum air 61 854 Btu in hr ft deg F Keff 15 0617 W m K Figure 8 83 New Keff assigned to each skip and debridged row Step 3 Define the Boundary condition and run the model to calculate the U factor for frame and edge of glass THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 86 8 SPECIAL CASES 8 8 7 Example 3 Skip and debridge A A 1 IM4353 wl Aoo 1433 i SB200 lt l a P if 19 A scale 1 20 0 0508 m 2 Scale 1 2 Note the skip trapezoid shall be treated as a rectangle equal to the total length of the base of the trapezoid Figure 8 84 Drawings for Example 3 Skip and Debridge THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 8 Non Continuous Thermal Bridge Elements 8 87 8 SPECIAL CASES 8 8 Non Continuous Thermal Bridge Elements STEP 1 Skip 0 0508 m 2 in Debridge Air 0 4318 m 17 in Interval 0 508 m 2 in 0 4318m 17 in 0 4826 m 19 in Note The rest of the example will be in SI units only with no IP unit translation
69. inches Z xy 2 202 6 129 dx dy 0 000 0 000 jen 0 000 Step 0 394 inches z Ready Head 4 Ready Jamb THERM sv_orthm E esl THERM Mron thm E E E File Edit Yiew Draw Libraries Options Calculation Window Help 18 x E File Edit View Draw Libraries Options Calculation Window Help l x OSHS BiboP tiatrteaQgegk F Cul OSHS B bosetialrLaqgsd amp F Eul tT 7 Sill Cross Section Glass orientation Up Gravity Arrow Down Cross section type Sill Vertical Meeting Rail Cross Section Glass orientation Up and Down Gravity Arrow Into screen Cross section type Vertical Meeting Rail JL Change E 4 x 6 463 1 450 ldx dy 0 112 2 562 len 2 564 Step 0 394 inches Y x y 121 0 186 3 dx dy 0 0 1 1 len 1 1 Step 10 0 mm Ready Sill Ready Vertical Meeting Rail Z 6 6 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 6 MODELING FRAME AND EDGE HEAT TRANSFER WITH THERM 6 3 Draw the Cross Sections 6 3 4 What is Not Modeled NFRC 100 specifically excludes certain options on fenestration products which are not modeled in THERM These options include Screen Systems Screen systems include trim stops that hold cover the screen Minor frame changes are allowed to accommodate the screen system and may be represented by a product offered without a screen Optional Interior trim Removable grilles applied to the int
70. metal in them A second option is to produce a single large sealed glass unit with muntins glued to the inside and outside surfaces while a grid is placed in the middle of one large insulated unit giving the visual effect of divided lights This reduces fabrication costs but does not reduce resistance to heat flow if the muntins in the middle are metal and if they touch both lights of glass THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 2 9 2 6 Improved Glazing Products 2 FENESTRATION PRODUCTS A third option which is more energy efficient is to build a large pane insulated unit that has snap on or elued on grilles to simulate the traditional lights The energy performance of the simple snap on grid will be similar to a unit without any mullions however the true divided lights will result in greater heat transfer because of the additional edges 2 6 7 Special Products Glass blocks present a very special case of double glazing They provide light with some degree of visual privacy Plastic blocks which have a lower U factor than glass are also available However when installed the necessary grouting reduces the energy efficiency Also metal mesh and steel reinforcing bars used between blocks to provide structural stability provide thermal bridges which also reduce energy efficiency Plastic glazings are available in a number of configurations with double layers Double glazed acrylic bubble skylights are formed with
71. of the product frame 2 Draw the geometry of the retracted venetian blind including the length and width of the stacked venetian blind slats and any continuous hardware that holds the blind in place top and bottom Note In this case the system seems to be floating because non continuous hardware is used to attach the blind to the fenestration system THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 153 8 SPECIAL CASES 8 14 Venetian Blinds Between Glass Integral 3 Insert the glazing system The example shown below has glazing layers that intersect the frame at two different heights There are numerous methods for modeling this The method shown is to stretch the glazing layers to meet the frame at the appropriate place and this method also necessitates inserting points on the glazing system for the correct boundary conditions segments Note Another method would be to insert float glass polygons for the glazing layer extensions this method eliminates the need to insert the points in the glazing system for the boundary condition segments In this example the edges of the glazing system intersect the frame at different heights so the edges of the glazing system are stretched to meet the frame Insert the glazing system at the bottom of the venetian blind assembly with Spacer height and Sight line to bottom of glass set to 0 Turn on Allow editing of IG polygon in Prefe
72. or lower glazing system to meet the other glazing system to enclose the IG THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 43 8 SPECIAL CASES 8 3 Dividers 8 Ifthe IG Unit is air filled then fill the cavities with NFRC Frame Cavity 100 assign the normal boundary conditions and simulate as usual If the IG unit if gas filled follow the procedures for gas filling a divider per Section 8 3 1 3 Because internal dividers are only modeled if the gap between the edge of the divider and the glass surface is less than 3 mm the 5 mm rule for linking glazing cavities and frame cavities does not need to be applied to internal dividers The frame cavity starts at the top and the bottom of the divider component Figure 8 45 Fill the cavities with Frame Cavity NFRC 100 THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 44 8 SPECIAL CASES 8 4 Storm Windows 8 4 Storm Windows Storm windows present a modeling problem different from most insulated glass IG units because the spacing between the IG unit and the storm window is usually quite large as shown in the figure below As with all other product modeling all relevant cross sections head sill jambs meeting rails and dividers must be modeled in THERM altos Fale Figure 8 46 Product with an interior storm window 8 4 1 Modeling Steps The following steps can be used to model storm windows These steps are discussed in more detail in the followi
73. rvity modifier BAA NA Unsealed storm panel Sealed IG so 5 mm Conv ction modifier N A N A 5 mm rule for linking rule for linking cavities applies cavities is NOT applied to the cavities around the spacer Link the cavity between the storm panel and the primary sash which has a throat of 25mm where it connects to the bottom glazing cavity to the glazing system cavity with the highest Keff ie the bottom cavity with a Keff 0 508 Figure 6 21 Link the cavity between the storm panel and the primary sash which is gt 5 mm to the glazing system with the highest Keff value THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 6 23 6 4 Importing Glazing Systems 6 MODELING FRAME AND EDGE HEAT TRANSFER WITH THERM 6 4 5 Condensation Resistance There are two ways to activate the Condensation Resistance model in THERM When importing the glazing system check the Use CR Model for Window Glazing System checkbox Inthe Options menu Preferences choice Therm File Options tab check the Use CR Model for Glazing Systems When inserting the glazing system into the model as discussed in Section 6 4 2 the value for the CR cavity height shall come from the table below If the real product height is not listed in the table below subtract 100 mm from the product height to use for the default glazing height for condensation modeling For example Swinging Doors in NFRC 100 Table 4 3 list a model height of 2090 mm
74. should be set to NFRC 100 2010 On the right hand side of the screen for each cross section component select the appropriate records from the Frame and Divider libraries When the frame cross sections and the glazing systems are specified click on the Calc button and WINDOW will calculate the total product U factor SHGC VT and CR shown in the lower left corner of the main screen In addition for obtaining NFRC rating values the program calculates the SHGCo SHGCi VTo and VT1 discussed in detail in the following section Figure 7 4 Window Library Detail View where the whole product is defined HH W6 3 Window Library C Users Public LBNL WINDOW6 w6 mdb File Edit Libraries Record Tools View Help lr ied amp Fa Md rn ieae i or List ID fi z Cale FS Name Picture Hi Set Mode Mode NFR to NFRC New Type Fixed picture Copy i Width 1200 mm Delete Height 1500 mm Save Area 1 800 m2 Set Report Tilt 90 Environmental Environmental Conditions Conditions to Heera NFRC 100 2010 NFRC 100 2010 Dividers Faa Display mode Select Cancel Find ID v 18 records found Normal Type Slze Width Height Layout Total Window Results mm mm U factor TOW m2 K Casement Double NFRC 2001 1200 0 1500 0 Horizontal Slider Casement Single NFRC 2001 600 0 1500 0 Single vision area SHGC 7 Door Transom NFRC 2001 2000 0 600 0 Single vision area WT
75. spacer is shown below For sealed glazing systems such as an IG the 5 mm rule for linking frame cavities and glazing cavities does not apply So in the example below the frame cavity inside the spacer as well as the two small cavities on either side of it all of which are connected to the glazing cavity are linked to the glazing cavity even though the connection throat to the glazing cavity is less than 5 mm For sealed IG units the 5 mm rule is not applied to frame cavities that touch the glazing cavity So in this example all the frame cavities that touch the glazing cavity are linked to it even if their throats are less than 5 mm Figure 8 76 Because the throat between the spacer opening and the glazing system cavity is lt 5 mm the two cavities are not linked THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 76 8 SPECIAL CASES 8 8 Non Continuous Thermal Bridge Elements 8 8 Non Continuous Thermal Bridge Elements Bolts skip and debridge thermal break including partially de bridged thermal break material and thermally slotted cross section shall be included in the model using the concept of isothermal planes The isothermal planes methodology calculates an effective conductivity of the bridging material based on area weighting the sections of the product with and without thermal bridging material based on the bridging material spacing dimensions This method is also valid for other regularly spaced thermal br
76. specific product its configuration and physical dimensions must be specified This includes the glazing properties visible total solar and infrared optical properties and thermal conductivity the gap gas air or low conductivity gas thermophysical properties spacer and frame characteristics and environmental conditions THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 4 1 4 2 WINDOW Computational Method 4 SUMMARY OF ALGORITHMS Fenestration product heat transfer through the center of glazing area is primarily a one dimensional process It is analyzed by breaking down the glazing system cross section into an assembly of nodes and calculating the heat transfer between each node Under steady state conditions the temperatures of the nodes are such that the net energy flux entering each node is equal to that leaving each node To perform the energy balance WINDOW models the user defined glazing system as a one dimensional steady state resistance network shown in Figure 4 1 An iterative solution method is then used to converge upon the correct temperature distribution From this temperature distribution any desired performance index can be calculated 1 Solar Radiation 1 Glazing Layer Figure 4 1 Resistance network used to model center of glazing heat transfer in WINDOW Two temperature nodes are assigned to each glazing layer front and back surface along with outdoor and indoor air temperature nodes The resist
77. tags THERM File Properties Cross section Type Sill Gravity Arrow Down BC Adiabatic U Factor Surface tag None BC NFRC 100 2010 Exterior Radiation Model Blackbody U Factor Surface tag SHGC Exterior BC Interior lt frame type gt convection only Radiation Model Blackbody U Factor Surface tag Frame L BC Adiabatic ff U Factor Surface tag None Figure 8 104 Bottom Rail Model for Rolling Door THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 113 8 SPECIAL CASES 8 10 Garage Rolling Doors 8 10 2 3 End Stile Model A nominal 2x4 wood block is used in the Stile Model The boundary condition type and the U factor tag used on Stile model are shown in the figure below THERM File Properties Cross section Type Jamb Gravity Arrow Into the Screen BC Adiabatic U Factor Surface tag None Model the greater of 63 5 mm 2 5 or into 25 4 mm 1 of core BC NFRC 100 2010 Exterior ana E F E Baa from outside edge of Radiation Model Blackbody wood framing member U Factor Surface tag SHGC Exterior l BC Interior lt frame type gt convection only Radiation Model Blackbody U Factor Surface tag Frame BC Adiabatic U Factor Surface tag None Figure 8 105 End Stile Model for Rolling Door THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 114 8 SPECIAL CASES 8 10 Garage Rolling Doors 8 10 2 4 Door Core Model The Door Core Model s
78. the Cross Section Type setting accessed from the File Properties menu It also depends on the orientation of the glazing system ie whether it is imported up down left or right The gravity vector can be displayed using the View Gravity Arrow menu See the THERM User s Manual for a discussion of the gravity vector The assumptions for each type of cross section are the following Head Cross Section Type Head glass imported facing down gravity vector is pointing down Sill Cross Section Type Sill glass imported facing up gravity vector is pointing down Jamb Cross Section Type Jamb glass imported facing up gravity vector is pointing into the screen Meeting Rail Cross Section Type Meeting Rail glass imported facing up and down gravity vector is pointing into the screen for a horizontal slider and gravity vector is pointing down for a vertical slider Temperature The program calculates the temperatures of the cavity walls based on the surrounding material temperatures and determines the heat flow direction based on the temperature differences It is not necessary to change the initial default cavity temperatures before the simulation After the simulation the calculated temperatures can be viewed by double clicking on a frame cavity Emissivity The program determines the emissivities of the frame cavity walls based on the emissivity values of adjacent materials If there are materials with different em
79. the second glazing system with the following settings and click the Add as additional glazing system radio button upon insert Set the Locator in the appropriate location for where the glazing system will start Orientation Down Actual Cavity height 1000 mm 39 inches Sight line to bottom of glass 0 Spacer height 0 Edge of Glass Dimension 63 5 mm 2 5 inches Glazing System Height 150 mm 6 0 inches Draw spacer Not checked Figure 8 42 Insert the lower glazing system THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 41 8 SPECIAL CASES 8 3 Dividers 5 From the Options menu select Preferences then click on the Drawing Options tab and check Allow editing of IG polygons so that the glazing system geometry can be modified 6 For both the upper and lower glazing systems move the points of the center glass layer into the caming as showin in the figure below For both the upper and lower glazing systems move the points of the center layer into the caming polygons Figure 8 43 Move the points of the middle layer of the upper and lower glazing systems into the caming THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 42 8 SPECIAL CASES 8 3 Dividers 7 For either the upper or lower glazing system move the points of the outer layers to meet the other glazing system to enclose the IG Figure 8 44 Move the points of either the outside layers of either the upper
80. these two different mounting styles Each mounting style has a slightly different definition of the adiabatic boundary condition and each will have a different projected frame length The rules for modeling can be found in NFRC 100 and the NFRC Technical Interpretations To model curb mounted skylights if the projected frame height is zero define a Frame U factor Surface Tag 0 25 mm 0 01 inches up the interior of the glass which will result in a non zero frame height Adiabatic boundaries no heat loss Frame Height Height f ac Rough Opening gt Surround panel not Surround panel not modeled in THERM modeled in THERM Figure 8 58 A flush mounted or inset mounted skylight Adiabatic boundaries no heat loss Rough Opening A gt Figure 8 59 A curb mounted skylight THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 59 8 SPECIAL CASES 8 5 Skylights 8 5 3 Example Flush Mounted Skylight Problem This example assumes a flush mounted skylight In WINDOW 1 Glazing System Library Make a glazing system with a tilt of 20 off horizontal In this example the glazing system is called Skylight Double Glz and is made up of generic glass layers se Window Library C Program Files _LBNL WISDOW63 5Sky light mdb joj x File Edit Libraries Record Tools wiew Help Coed st aeaa MaB emi Ole Glazing System Library List Cale F3 Dje Name Skylight Double Gle H
81. thm C Program Files LBNLSWINDOW63 S ampl s sample sill_ O07 thm C Program Files LBNLAWINDOW63 S ampl s sample sill_011 thm Stop Current Calculation Glazing Options Multiple files with multiple glazing options can be added to the Calculation Manager using the Calculation Calc Manager menu choice To see the status of the simulations go to Calculation Calc Manager click on the Log button and the status of each file will be displayed only for this THERM session E Calculation Log Click on a column to sort Run Time Filename Message Status 4 Clear Log Tue 4ug 31 17 28 39 2010 C Program FilesS LENLSWINDOWES S amples sample sill011 thm Calculation complete OF koy 1 766 4 810 dx dy 1 156 3 49 Tue Aug 31 17 28 38 2010 C Program FilessLBNL WINDOW63 3 amples sample sill 007 thm Calculation complete OK oes Sse a Tue Aug 31 17 28 37 2010 C Program Files LENLSWINDOWE6S S amples sample sill 011 thm Calculation complete OF i Tue Aug 31 17 28 35 2010 C Program Files LBNLSWINDOWE Samples sample sil 008 thm Calculation complete OK Tue 4ug 31 17 28 30 2010 C Program FilesSLENLSWINDOWES S amples sanmple sill_011 thm Calculation complete OF Tue 4u0 3 17 28 28 2010 C Proorarn FilesSLENLSWINDOWES4S amolessamole sill 007 thm Calculation complete OF F igure 6 35 The Calc Manager can be used to simulate multiple files with multiple glazing options in each file 6 42 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation
82. tints If larger reductions are desired a reflective coating can be used to lower the solar heat gain coefficient by increasing the surface reflectivity of the material These coatings usually consist of thin metallic layers The reflective coatings come in various metallic colors silver gold bronze and they can be applied to clear or tinted glazing the substrate The solar heat gain of the substrate can be reduced a little or a lot depending on the thickness and reflectivity of the coating and its location on the glass As with tinted glazing the visible light transmittances of reflective glazings are usually reduced substantially more than the solar heat gain 2 6 3 Double Glazing Storm windows added onto the outside of window frames during the stormy winter season were the first double glazed fenestration products They reduce infiltration from winter winds by providing a seal around all the operating sash and they improve the insulating value of the glazing as well When manufacturers began to experiment with factory sealed double pane glass to be installed for year round use they encountered a number of technical concerns such as how to allow for different thermal movement between the two panes how to prevent moisture from forming between the panes and condensing on an inaccessible surface and how to allow for changes in atmospheric pressure as the assembly was moved from factory to installation site These issues have been succ
83. unit there are several possible remedies Most manufacturers who offer non sealed double glazing include a small tube connecting the air space to the outside air which tends to be dry during winter months Check to be sure that the inner glazing seals tightly to the sash and clear the air tube if it has become obstructed In some cases reducing interior room humidity levels may help alleviate the problem THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 3 9 3 6 Infiltration 3 FENESTRATION HEAT TRANSFER BASICS 3 6 Infiltration Infiltration is the leakage of air through cracks in the building envelope Infiltration leads to increased heating or cooling loads when the outdoor air entering the building needs to be heated or cooled Fenestration products and doors are typically responsible for a significant amount of the infiltration in homes In extreme conditions depending on the type and quality infiltration can be responsible for as much heat loss or gain as the rest of the product The level of infiltration depends upon local climate conditions particularly wind conditions and microclimates surrounding the house Typically U factor and SHCG effects far outweigh infiltration effects Tight sealing and weatherstripping of the fenestration product including sash and frames is of paramount importance in controlling infiltration High quality fixed fenestration products help to reduce infiltration because they are easier to seal and keep t
84. viewing merchandise through a store window on a bright day special coatings can virtually eliminate this reflective effect The reflectivity of glass can be increased by applying various metallic coatings to the surface Early processes used a liquid alloy of mercury and tin to create mirrors A silvering process developed in 1865 improved the performance of mirrors Today mirror like surfaces can be created by using vacuum deposited aluminum or silver or with a durable pyrolytic coating applied directly to the glass as it is manufactured Thick coatings can be fully reflective and virtually opaque a thinner coating is partially reflective and partially transmitting Most common coatings reflect all portions of the spectrum However in the past twenty years researchers have learned a great deal about the design of coatings that can be applied to glass and plastic to reflect only selected wavelengths of radiant energy Varying the reflectance of far infrared and near infrared energy has formed the basis for low emittance coatings for cold climates and for spectrally selective low emittance coatings for hot climates 3 7 3 Absorptance Energy that is not transmitted through the glass or reflected off of its surfaces is absorbed Once glass has absorbed any radiant energy the energy is transformed into heat raising the temperature of the glass Typical 1 8 inch 3 mm clear glass absorbs only about 4 percent of incident sunlight The absorpta
85. weighted method 4 1 3 The area weighted method 4 1 3 shall be used 2 Frame and divider SHGC s shall be calculated in accordance with Section 4 2 2 The alternate approach in section 8 6 shall not be used Note current research is aimed at assessing which method is more accurate at some point in the future this recommendation may be revised 3 Section 6 4 refers the issue of material properties to national standards Material conductivities and emissivities shall be determined in accordance with the NFRC Simulation Manual or more currently adopted NFRC standard on this topic 4 Section 7 on Shading Systems is currently excluded from NFRC procedures 5 Section 8 2 addresses environmental conditions The following are defined by NFRC For U factor calculations Tin 21 C Tout 18 C V 5 5 m s Tim out Tout Tim in Ti 1 0 W m For SHGC calculations Tin 24 C Tout 32 C V 2 75 m s Tim out Tout Tim in Ti 1 783 W m THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 A 1 A 2 6 APPENDIX A The Application of ISO 15099 to NFRC 100 and 200 Section 8 3 addresses convective film coefficients on the interior and exterior of the window product In section 8 3 1 NFRC simulations shall use the convective heat transfer coefficient based on the center of glass temperature and the entire window height this film coefficient shall be used on all glass and edge of glass indoor surfaces Frame section indo
86. window frame that are exposed to the warm interior air 2 3 Performance Implications of Basic Fenestration Types There are subtle performance differences between a fixed and operable fenestration product that fills an identical rough opening The fixed unit will typically have a smaller fraction of frame and proportionately more glass than the similar operable unit Thus fixed products with high performance glass will have a better lower U factor but a higher SHGC due to a smaller frame area and larger glass area Fixed products have very low infiltration rates but then they also do not provide natural ventilation and do not satisfy building code requirements for fire egress For operating fenestration products the type of operation has little direct effect on the U factor or SHGC of the unit but it can have a significant effect on the air infiltration and ventilation characteristics Operation can be broken into two basic types sliding products and hinged products The comments below are a general characterization of American fenestration products however they may not apply to a specific product made by a given manufacturer 2 3 1 Hinged Windows Hinged windows such as casements awnings and hoppers generally have lower air leakage rates than sliding windows from the same manufacturer because the sash closes by pressing against the frame permitting the use of more effective compression type weatherstripping In most types the sash swing
87. x OK Degrees zo a Clockwise eee C Counterclockwise oil x y B5 7 237 9 dx dy 164 3 18 3 len 165 3 Step 10 0 mm Ab has been changed to Sill NUM 4 s of y 236 4 126 8 dx dy 182 7 192 5 len265 4 Step 10 0 mm y Ready Sill NUM 4 Figure 8 63 Rotate the sill cross section AFTER assigning Boundary Conditions THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 63 8 SPECIAL CASES 8 5 Skylights BC NFRC 100 2010 Exterior U factor tag None 150 mm 6 0 glass height BC Adiabatic U factor tag None 63 5 mm 2 5 BC NFRC 100 2010 Exterior U factor tag SHGC Exterior edge of glass BC lt glazing system name gt U factor Inside Film Radiation Model AutoEnclosure U factor tag None BC lt glazing system name gt U factor Inside Film Radiation Model AutoEnclosure U factor tag Edge BC Adiabatic U factor tag i ee Figure 8 64 Boundary condition and U factor tag settings for skylight Sill example BC Interior 20 tilt lt frame type gt Frame Convection only Radiation Model AutoEnclosure U factor tag Frame 6 Check the Gravity Vector for the Sill cross section View Gravity Arrow which should point m down xj jel 7 Simulate the file THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 64 8 SPECIAL CASES 8 5 Skylights 8 Click on the Show U factors button to view the U factors dialog box Make sure that the projection is set to
88. 0 CODE Figure 8 164 Import the appropriate records from the CGDB Shading Layer Library THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 178 8 SPECIAL CASES 8 14 Venetian Blinds Between Glass Integral If only one slat geometry is represented in the CGDB import that record into the working database and then make new records for the missing slat geometries so that there is a separate Shading Layer record for both the Open and Closed geometries Shading Layer Library ID a000 Mame olim White VB Closed Product Mame Slim White Venetian Blind Manufacturer Pela 2000 ET The Material references a Type Venetian blind horizontal record in the Shade Material Material Library which is automatically created when the Shading Layer is Effective Openness Fraction 0 000 imported from the CGDB Venetian Blind Slat width fAs mm fo Spacing 127 mm Tilt closed 90 Tit angle 8 H eee Blind thickness 05 mm Rise 0 838 mm Figure 8 165 Define the venetian blind geometry for the closed vertical slats e Type Venetian blind horizontal e Material White Venetian Blind Slat this pulldown references the record in the Material Library that is associated with this Shading Layer When a Shading Layer is imported from the CGDB the associated record for the material is automatically added to the Shade Material Library If you need to make a new Shading Layer record for a different slat geo
89. 00 0 840 0 840 1 000 Gapi kr 10 Argon 954 19 4 L Glass 2 ee 2016 E145 3 CIG 3 0 K 0342 0258 0240 0497 0070 0136 0 000 0102 0 840 1 000 me pera Report dadi Ufactor 5C SHGC Rel Ht Gain Wm Wma 0 6863 0 5971 442 For Help press Fl Mode NFR SI NUM A Figure 9 14 WINDOW Glazing System Library for Glazing Option 1 of the aluminum slider window THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 9 17 9 3 Problem 2 Aluminum Horizontal Slider Window 9 SAMPLE PROBLEMS The results for the center of glazing U factor are shown in the following table Table 9 9 Center of glazing U factor Results for Glazing Option 1 from WINDOW Center of glazing U Factor Glazing Options 25 4 mm 1 0 overall thickness These glazing systems will be used in THERM to calculate the frame and edge of glazing U factors and also in WINDOW to calculate the overall product U factor 9 3 4 Edge of glazing and Frame Modeling THERM There are seven cross sections that must be modeled for this product listed in the table below Table 9 10 Cross sections and files associated with the aluminum horizontal slider example Note The sample THERM files for this example were modeled with Glazing Option 1 only Spacer geometry must be altered to accommodate the remaining glazing options Create THERM files for each cross section The DXF files were not generated in a manner that would facilitate the use of the AutoConvert fu
90. 00000 WT 0 67546 0 72581 0 70099 ok eren H Save As Save in J WINDOWS Click on the Save As FE NATE Aa button to save the results into a text file H AngularCalcDetailedReport Olazing 10 25 2012 4 55 PM Text Document H AngularCalcDOE2Report WholeWi 10 25 2012 4 53 PM Text Document di BSDFs 5 14 2013 1 53 PM File folder di Debug 5 14 2013 1 52 PM File folder Samples 4 22 2013 5 17 PM File folder W XML 11 15 2012 6 34 PM File folder 4 mI File name Save as type Tesd files tt EJ Microsoft Excel SHGCO1 ExE Oo x pat File Edit View Insert Format Tools Data Window Help Adobe POF fal es The text file can be imported into other software such as a spreadsheet SPAS Pi Se SS alas p Mo Dividers Generic Dividers Generic Dividers i 19 05 30 1 0 00319 0 00613 0 00892 0 87050 0 79157 0 70985 0 0 0 0 87539 0 75574 0 70093 EE vale NUM we Figure 7 8 The SHGC 0 amp 1 and VT 0 amp 1 results can be saved to a text file which can be imported into other applications such as a spreadsheet or word processing program THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 7 9 7 4 Overall Product U factor SHGC VT and CR Calculations 7 TOTAL PRODUCT CALCULATIONS USING WINDOW 7 4 2 Sightline Grouping Procedures In order to reduce the number of simulations required to develop the SHGC values for a product line with varying frame widths the following grou
91. 013 7 1 7 3 Center of Glazing U factors from WINDOW 7 TOTAL PRODUCT CALCULATIONS USING WINDOW 7 3 Center of Glazing U factors from WINDOW The WINDOW User s Manual contains detailed information about calculating the center of glazing U factors For an NFRC simulation create glazing systems that represent all the glazing types to be modeled from the glass matrix provided by the manufacturer In WINDOW access the Glazing System Library List View either from the Libraries Glazing System menu by clicking on the Glazing System Library toolbar button or by pressing F5 FA W6 3 Glazing System Library C Users Public LBNL WINDOW6 w6 mdb File Edit Libraries Record Tools View Help a EJE Saem oy Glazing System Library C 4Users Public LE NLY IN D OW 6 wwe mdb Detailed View E ee Mode Tilt poate Keft ae Uval Wi nek rari Wi miz E NFAC 100 2010 0 033 18 50 1 773 0 618 0 710 NFAC 100 2010 0 064 24 00 2 699 0 704 0 809 Sram low E E Sl Double Clear Air ss Delete Double Low e Air 3 a NFRC 100 2010 g0 NFRC 100 2010 g0 NFRC 100 2010 g0 NFAC 100 2010 g0 NFRC 100 2010 g0 NFRC 100 2010 g0 NFRC 100 2010 Ein Double Clear with Argon Triple Clear 3mm Low e air 3mm Clear Advanced Sample Glesvs Sample GleSye w Int Blue VB HH H HH FH 9 records found Export Report Print Figure 7 2 WINDOW Glazing System Library For NFRC certified simulations use the currently approved International Glazi
92. 284 0 01590 0 4261 With Dividers gt 1 25 4mm modeled at 0 75 SHGC 0 01850 0 5971 0 62632 0 01850 0 3814 Table 9 14 Total product SHGC for the best glazing option Clear Argon Low E Dividers Dividers lt 25 4 mm modeled gt 25 4 mm modeled at 19 5 mm lt 1 0 at 38 1 mm gt 1 5 modeled at 0 75 modeled at 1 5 Clear Argon Low E 0 4735 0 4261 0 3814 VT Calculation Using Equation 4 2 from NFRC 200 Using Equation 4 2 from NFRC 200 and the data from Table 9 13 calculate the whole product VT from the VTo VT and VTc VT VTo VIc VTi VTo Glazing Option No Dividers Without Dividers VT 0 0 0 4521 0 77090 0 0 0 3485 With Dividers lt 1 25 4mm modeled at 0 75 VT 0 0 0 4521 0 68694 0 0 THERM6 3 WINDOWG6 3 NFRC Simulation Manual June 2013 9 29 9 3 Problem 2 Aluminum Horizontal Slider Window 9 SAMPLE PROBLEMS 0 3106 With Dividers gt 1 25 4mm modeled at 0 75 VT 0 0 0 4521 0 60782 0 0 0 2748 Table 9 15 Total product VT for the best glazing option Clear Argon Low E Dividers Dividers lt 25 4 mm modeled at gt 25 4 mm modeled at na 19 5 mm lt 1 0 38 1 mm gt 1 5 Glazing Option No Dividers modeled at 0 75 modeled at 1 5 Clear Argon Low E 0 3485 0 3106 9 3 7 Drawings for Aluminum Horizontal Slider The following pages contain detailed drawings for this window Sill Vent
93. 3 5 mm 2 5 inches This dimension will be added above the sight line defined by the Sight line to bottom of glass dimension when importing the glazing system None Use this tag for the 86 5 mm 3 5 inches of glazing system that is modeled above the Edge of glazing and for the glazing system exterior boundary condition This is the default U factor tag automatically assigned by THERM for all surfaces except the glazing system SHGC Exterior Use this tag for all exterior non glazing surfaces This tag is used to calculate the wetted length of the exterior frame to be used in WINDOW for the Solar Heat Gain Coefficient SHGC calculation The Blocking Surface checkbox should be checked for frames but not for glazing systems To change the boundary condition for one boundary segment double click on the segment or single click and press Enter and the Boundary Condition Type dialog box will appear This dialog box allows specification of both the boundary condition and the U factor tag at the same time To change the boundary condition for multiple boundary segments cl ick on the first segment and double click or single click and press Enter on the last segment in a counterclockwise direction The choices made in the Boundary Condition Type dialog box will then be applied to all the selected boundary segments It is also possible to change the boundary condition definition for boundary segments using the Select Material BC toolbar button Cl
94. 3 NFRC Simulation Manual June 2013 8 56 8 SPECIAL CASES 8 5 Skylights 8 5 Skylights This section discusses the modeling procedures for skylights which are modeled in sections in a similar manner to other products In addition in accordance with NFRC 100 skylights are modeled at a 20 slope from horizontal 8 5 1 Skylight Modeling Steps The steps for modeling a skylight are as follows In WINDOW Create the skylight glazing system in WINDOW Set Tilt to 20 degrees In THERM Draw the required frame cross sections in THERM for example a head sill and jambs if they are all different untilted Because the tilt of the jambs will be in the z direction which is not possible to display in the two dimensional viewing of THERM they will be drawn vertically and the gravity vector oriented properly to reflect the tilt in the z direction Do not use the Condensation Resistance Model on any of the THERM skylight cross sections WINDOW will calculate the CR value based on the temperatures from the U factor results Even if the THERM cross sections are modeled with CR enabled WINDOW will use the U factor temperature results rather than the CR temperature results when calculating the whole product CR value Set the Cross Section value in File Properties as follows For Sill set Cross Section to Sill Gravity Vector should face Down For Head set Cross Section to Head Gravity Vector should face
95. 323 81 6 These CR numbers are based gfi To and Ti as defined in the INI F Protected For Help press F1 Mode NFRC si Num Z For Product Type Sill not rotated the CR calculation will be based on the THERM CR simulation se Frame Library C Program Files LBNL WINDOWG63 w6 mdb loj x File Edit Libraries Record Tools Yiew Help wm ES A AEEA a rE A Frame Library ID 6 Therm Name sample jamb THM New Source Them x Type ab O Copy List Filename 55 amplesssample jamb THM Browse U VALUES Save Frame 1 996 W m2 K Edge Correlation v Edge of Glass 2 343 W m2 K Delete ddadda m GLAZING SYSTEM Width 26 5 mm Center of Glass U value 1 934 W m2 K FRAME Projected Frame Dimension 42 3 mm Material Abs 0 300 Color p Wetted Length 41 2 mm Comment m Condensation Resistance based on Therm U factor simulation 30 RH 50 RH 70 RH Overall Frame 0 002 0 018 0 053 97 6 Edge 0 007 0 132 0 263 86 6 These CR numbers are based on To and Ti as Hefined in the INI Protected For Help press F1 Model NFRC SI NUM YA For Product Type Jamb not rotated the CR calculation will be based on the THERM U factor simulation Figure 6 23 WINDOW Frame Library Detailed View displays the type of THERM temperature data to be used with the CR calculation either U fator or CR 6
96. 5 Saving Layers to the User Database You can save a glazing layer with an applied film to the user database if it has a different filename from any layer currently in the user database or in the IGDB If you save a layer that has components such as a glazing layer that has an applied film the component layers will be saved to the user database at the same time unless they already exist in the IGDB or user database This allows you to load and edit those layers at a later time To save a layer to the user database Select the layer or system to save by clicking on a layer button Click the Save button on the toolbar or Choose menu option File Save filename or Right click to display the pop up menu and select the option Save filename If the layer or system you saved had components or if the save operation fails you will be asked Do you want to view the details of the save operation If you answer yes you can view information about components that were saved to the user database and components that were not saved to the user database along with an explanation of why some components were not saved Note to change the filename and save in one operation choose menu option Save As instead Note You cannot save data for a layer with the same filename as another layer in the IGDB or your current user database If a conflict is detected Optics will ask you to rename the layer before saving it or cancel the import
97. 6 0 78561 0 70039 calculated for No Dividers Dividers lt 25 4 mm 1 and Dividers 25 4 mm 1 oK Figure 7 6 Click on the Detail button to get the SHGC 0 amp 1 and VT 0 amp 1 results THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 7 4 Overall Product U factor SHGC VT and CR Calculations 7 TOTAL PRODUCT CALCULATIONS USING WINDOW If the product has real dividers the program will calculate the SHGC 0 amp 1 and VT 0 amp 1 values for the generic dividers as well as for the actual dividers as shown below For NFRC simulations the default divider results should always be used 7 8 Results for actual Results for default dividers dividers modeled in the window SHGC and VT detail Actual Mo Generic Generic Dividers Dividers Dividers Dividers POD mm 15 856000 H A 19 05000 ae 10000 SHGECO 0 00411 0 00353 0 0064 0 00925 SHGCI 0 80450 0 87899 0 79228 0 71025 YTO 0 00000 0 00000 0 00000 0 00000 YTI 0 80035 0 87546 0 72581 0 70099 ox Beem Figure 7 7 The SHGC 0 amp 1 and VT 0 amp 1 results are shown for the actual dividers if they are modeled June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 7 TOTAL PRODUCT CALCULATIONS USING WINDOW 7 4 Overall Product U factor SHGC VT and CR Calculations SHGC and VT detail Mo Benere Generic Dividers Dividers Dividers POD mm MHA 13 05000 ae 10000 SHGCO 0 00353 0 00647 0 00925 SHGC1 0 87099 0 79228 0 71025 VTO 0 00000 0 00000 0
98. 6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 90 8 SPECIAL CASES 8 9 Site Built fenestration products Curtain Walls Window Walls and Sloped Glazing whether it is a curtain wall window wall or sloped glazing are simulated as 1 2 the full height for head and sill or width for jambs The vertical mullion is always simulated full width Modeling Procedures Curtain Walls See the modeling steps in the following section sik Intermediate vertical frames l J l Seoocsos ee a ee ee ee ee ee eel ee l Modeled as Head but 1 2 Modeled as height Mullion full Intermediate horizontal Modeled as frames Jamb but width Modeled as Sill but 2 height Figure 8 86 Curtain Wall Modeling Method Window Walls For window walls the standard head and sill members are modeled and therefore the steps for simulation are identical to that of a normal window cross section Modeled as Head full Modeled as height Mullion full width Modeled as Jamb but width Modeled as Jamb but 1 2 Modeled as Sill width full height Figure 8 87 Window Wall Modeling Method Sloped Glazed Wall System If the product to be simulated is a sloped glazed wall system then the modeling steps are identical to a curtain wall or window wall except that the cross section is to be sloped 20 degrees see skylight section for instruction on sloping products THERM6 3 WINDOW6 3 NFRC Simulation Manual Ju
99. 67 0 0004 0 0568 0 1772 0 0781 Dewpoint C 29 10 3 15 4 8 T T E E E E 5 5 Figure 7 5 Window Library Detail View where the whole product results are calculated and displayed THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 1 5 7 4 Overall Product U factor SHGC VT and CR Calculations 7 TOTAL PRODUCT CALCULATIONS USING WINDOW 7 4 1 Individual Product SHGC and VT SHGC 0 amp 1 VT 0 amp 1 It is not necessary to calculate the SHGC and VT for all individual products and associated model sizes NFRC 200 outlines a procedure for determining SHGCo SHGC VTo VTi values which can then be used to calculate the SHGC and VT of any individual product This procedure is used to obtain NFRC rating values These values are calculated in WINDOW for the best glazing option modelled with the highest combined frame and edge heat loss i e the option with the lowest center of glass U factor and the highest total product U factor as outlined in NFRC 200 Section 4 2 3 A The values calculated from that one case are then used to calculate the SHGC and VT for any other glazing options using Equations 4 1 and 4 2 in NFRC 200 For domed skylights see Chapter 8 of this manual it is necessary to use the tested value for the center of glass value with the modelled frame and edge values The values are calculated for the product using the best glazing system for three cases No dividers Dividers lt 25 4 mm 1 modelled at
100. 7 O Lyer e s e E Filename CLEAR BLUGR Optiw3 l N T ane ES 8 wa f Types Filename xpatame _ Npenal cm Nominal Gn Thins Manufacturer NFRC_ID__ Acceptance Appearance SPET Maes mwt par ie n Laminate EmitF ae E mitB i 102 Bluegreen dup 9811 usr 2 WS5_NFRC_2003 i RobinOpticsDatabase mdb Spectral Properties Filename 102 Bluegre 102 Bluegreen dup 9811 usr TUV T 0 030 SPF T 159 164 tow T 0559 EmitF 0 840 Emitg 10 840 Wavelength microns Transmission Reflectance ront Reflectance back The name of the User Database is displayed on this button Figure 8 118 Select the User Database to see the constructed laminates and the associated interlayers THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 128 8 SPECIAL CASES 8 11 Creating a Laminate in Optics for NFRC 8 11 3 15 Importing the Laminate into WINDOW from the Optics User Database In WINDOW in File Preferences go to the Optical Data tab and set the second option Optics User Database to your Optics user database which by default is called UserGlazing mdb but it can have any name with the mdb extension you can browse to the file with the browse button its default location is in Program Files LBNL LBNL Shared directory Options Thermal Cales Optical Cales Optical Data Updates Use the following database for optical data f GDB or IGDB Update LENL Shared Glazing IGDB29 Chromo
101. 7 Door NFRC 2001 960 0 2090 0 Single vision area Double Door NFRC 2001 1920 0 2090 0 Horizontal Slider i ixed picture 1200 0 1500 0 Single vision area CH Fixed picture NFRC 2001 Single visi Garage door NFAC 2001 3000 0 2400 0 Single vision area Horizontal Slider NFRC 2001 1500 0 1200 0 Horizontal Slider Projecting 4wing Dual NFAC 2001 1500 0 1200 0 Vertical Slider Projecting 4wning Single NFAC 2001 1500 0 600 0 Single vision area Sidelite NFAC 2001 600 0 2000 0 Single vision area Skylight NFAC 2001 1200 0 1200 0 Single vision area Vertical Slider NFAC 2001 1200 0 1500 0 Vertical Slider Sliding Glass Door NFAC 2001 2000 0 2000 0 Horizontal Slider Glazed Wall System NFAC 2001 2000 0 2000 0 Horizontal Slider Custom Dual Vision Horizontal Custom 1500 0 1200 0 Horizontal Slider Custom Dual Vision Vertical Custom 1200 0 1500 0 Vertical Slider Custom Single Vision Custom 600 0 1500 0 Single vision area 7 4 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 7 TOTAL PRODUCT CALCULATIONS USING WINDOW 7 4 Overall Product U factor SHGC VT and CR Calculations Once the values have been calculated the results are displayed in the Total Window Results section as shown below The Detail button next to the SHGC and VT results can be used to view the SHGCo SHGCi VTo and VT values and the Detail button next to the CR result is used to view the intermediate values used to determine the overall CR result EA W6 3 Window L
102. 705 so 63 5 90 0 Projected in Glass Plane 5 E t Error Energy Norm Sor Emot 7 Figure 9 52 THERM cross section and U factor results for the door lite cross section THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 9 59 9 5 Problem 4 Door 9 SAMPLE PROBLEMS Door Lite Jamb BC Adiabatic U Factor Surface tag None Modeling Assumptions Cross Section Jamb Gravity Arrow Into the screen BC NFRC 100 2010 Exterior Radiation Model Blackbody U Factor Surface tag None BC 3 mm Clear Air Clear U factor Inside Film Radiation Model AutoEnclosure U Factor Surface tag None BC 3 mm Clear Air Clear U factor Inside Film Radiation Model AutoEnclosure U Factor Surface tag Edge BC NFRC 100 2010 Exterior Radiation Model Blackbody U Factor Surface tag SHGC Exterior BC Interior Wood Vinyl Frame convection only Radiation Model AutoEnclosure U Factor Surface tag Frame BC Adiabatic U Factor Surface tag None x U factor delta T Length Wife FE L mm Rotation Frame 2 8372 39 0 42 0624 30 0 Projected in Glass Plane SHGC Esterior 2 6078 so 42 0624 90 0 Projected in Glass Plane Edge 2 2705 39 0 63 5 90 0 Projected in Glass Plane Error Energy Horm 5 90 Export l Figure 9 53 THERM cross section and U factor results for the door lite cross section 9 60 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Man
103. 8 0 000 photopic Ab Select the Lamin J q Select the File Save As menu New Laminate Ctrl M D D oc oo 2 D Edit Laminate Chrl O i EmitF 0840 0 000 option Emith Iqnean joo Save CalcLam usr Ctrl 5 alcLam usr 45 Export CalcLam usr Text File ctrl E Export CalcLam usr Radiance File Export CalcLam usr Warnings File Import Text File s ctl Mew Filename leave extension blank to use default extension Print Screen Cancel Exit Type the desired name for the new 102 ancevat quamarine 9811 ust laminate Optics will automatically add the usr extension This new record will be automatically added to the Optics User Database set in Tools Options Figure 8 117 Save the final laminate using the naming convention of lt glass layer ID gt lt interlayer name gt lt glass layer ID gt THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 127 8 SPECIAL CASES 8 11 Creating a Laminate in Optics for NFRC The laminate construction called in this case ClearLaminate usr as well as the Interlayer used in the laminate is saved in the User Database The glass layers on either side of the Interlayer are not saved in the User Database because they are found in the IGDB Select User Database from the pulldown list to see the records in the User Database ii Optics File Edit Database View Tools Graph Help oe d aa User Database
104. 8 21 8 SPECIAL CASES 8 3 Dividers 8 3 2 Simulated Divided Lites A simulated divided lite is a glazing system that has elements attached to the inside and outside of a glazing system to give the appearance of true divided lites The glazing system has a metal internal reinforcement but is all one system The materials applied adhered to the outside of the insulating glazing unit are not required to be modeled per NFRC 100 This is an option of the manufacturer and the following provides the details to model and simulate it correctly Internal dividers such as the dividers in the glazing system gap for simulated divided lites are an exception to the rules for linking frame cavities to glazing cavities as discussed in Chapter 6 Internal dividers are only modeled if the distance between the exterior sides of the divider and the inside surface of the glazing system are less than or equal to 3 mm Therefore even for contoured internal dividers a simplifying assumption is made that the 5 mm rule is not applied The space between the divider edge and the glass are modeled as frame cavities with either air filled or gas filled as needed and the boundary of that cavity extends to the top and bottom of the divider component See the following examples for detailed descriptions THERM 6 3 SimulatedDividedLite THM _ O x fs File Edit View Draw Libraries Options Calculation Window Help lej x De SiBiboP imdtrhb aged Feule UC F 4
105. 80 0 065 0 053 0 053 0 533 0 056 0 486 0 834 0 771 0 609 0 156 0 244 0 368 0 381 0 238 0 354 0 274 0 130 0 224 0 207 0 317 0 158 0 075 0 070 0 060 0 546 0 467 0 353 0 316 0 113 0 089 0 299 0 612 0 538 0 525 0 455 0 075 0 070 0 061 0 616 0 318 0 415 0 403 0 108 0 092 0 394 0 610 0 532 0 520 0 448 0 899 0 884 0 617 0 222 0 343 0 721 0 722 0 201 0 316 0 420 0 223 0 353 0 322 0 453 0 095 0 083 0 080 0 062 0 417 0 238 0 088 0 095 0 132 0 098 0 059 0 383 0 300 0 296 0 235 0 056 0 083 0 080 0 063 0 476 0 156 0 088 0 096 0 116 0 088 0 066 0 361 0 275 0 272 0 211 0 140 emis 0 000 0 000 0 000 0 000 0 000 0 000 0 000 0 000 0 000 0 000 0 000 0 000 0 000 0 840 0 840 0 840 0 840 0 840 0 840 0 840 0 840 0 840 0 840 0 840 0 840 0 840 0 000 0 840 0 000 0 840 0 000 0 840 On the left hand side of the screen of particular interest is the NFRC only checkbox if checked only the records with a in the Mode column will be displayed which are the records certified for NFRC simulations Detailed View Click on this button to see all the information about the currently highlighted record The optical properties defined for each glass entry are listed below ID The unique ID associated with this record For records whose Source is Optics this ID is the NFRC ID from the International Glazing Database For records whos
106. 890 Tvis gt 0 890 Glass that meets this criteria includes 3mm clear glass 3 mm low iron glass 6 mm low iron glass This ensures that an applied film layer in Optics will always have a similar or lower transmittance than the reference substrate which determines the applied film properties Substrate layers the base glass to which the applied films are applied are measured separately without the applied films attached and submitted to the IGDB This is the responsibility of the manufacturer submitting data to the IGDB as discussed below The applied film manufacturer can submit to the IGDB two spectral data files single 3 mm clear with the applied film on a clear substrate and the clear substrate by itself With this data in the IGDB simulators using this Applied Film Procedure can then create the other two cases the single 6 mm clear with the film and the single 6 mm gray with the film to do the SHGC and VT calculations THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 132 8 SPECIAL CASES 8 12 Creating an Applied Film Layer in Optics for NFRC Certification This will allow a film manufacturer to submit to the IGDB several different films with the same clear substrate if they are all measured on the same clear 3 mm substrate from the same glass batch For example if a film manufacturer wanted to submit data for 20 different applied films they would submit one spectral data file for the substrate of all 20 measurements as
107. A Display the results for the SHGCo SHGCi VTo and VTi for the best glazing option Clear Air Clear as shown in Figure 9 40 se W6 Window Library C Program Files LBNL WISDOW63 Sk ylight mdb File Edit Libraries Record Tools View Help Coad SO S Bli unde ronl Ho ei OF Name Skylight 3mm Generic Mode NFRC Type Skylight ka gt width 1200 mm Best Glazing Height 1200 mm Option Area 1 440 m2 Tit 0 Environmental Conditions C Dividers NFRC 100 2010 Dividers Display mode SHGC and T detail x Normal l Total Window Results Ho Generic Generic U factor 3 57206 whime K Dividers Dividers Dividers SHGC 0 66235 Se POD mm MA 19 049999 38 099998 etall vT 0 7074 0 002958 0 005795 0 008483 CR 36 Detail 0 864762 0 781443 0 702511 Click the Detail 0 000000 0 000000 0 000000 0 867 802 0 7 P5646 0 694027 button to display the SHGCo SHGC VTo VTi values ea For Help press Fl 9 42 June 2013 x eee Figure 9 40 Window Library record for the best glazing option THERM6 3 WINDOW6 3 NFRC Simulation Manual 9 SAMPLE PROBLEMS 9 4 Problem 3 Flush Mount Skylight Table 9 21 SHGCo SHGC1 VIo and VT data for the best glazing option in this product line Clear Air Clear Dividers Dividers lt 1 25 4 mm gt 1 25 4 mm No Dividers modeled at 0 75 modeled at 1 5 0 864762 0 781443 0 702511 0 861802 0 775647 0 694027 SHGC C
108. ASES 8 12 Creating an Applied Film Layer in Optics for NFRC Certification 8 12 4 2 Adding an Applied Film to a Coated Layer You can apply a film to the uncoated side of a coated glazing creating a double coated layer with the coating on one side and the film on the other To apply a film to a coated layer Click on the Glazing System tab Add the desired layer to a layer column under the Glazing System tab Select the coated layer by clicking on the desired layer number button Choose the menu option Edit Change Add Film OR Right click on the selected glazing layer button and select the choice Add Film The Change Glazing dialog box will appear The film name box is highlighted in blue click on it to select an applied film from the database you must select an Applied Film layer not a Film layer You must choose a film that is on the Approved Applied Films list The new film will be applied to the uncoated side of the glazing to create a double coated layer with the film on one side and the coating on the other this is indicated in the Apply Film to section of the dialog box You will be prompted to enter a new name for the glazing Use the naming convention specified in the beginning of this document i e NFRC IDs for both the glazing layer and the applied film If you want to keep the new layer save it to the user database see Saving Layers to the User Database 8 12 4 3
109. AZING WITH WINDOW 5 3 Glazing System Library Center of Glazing U factor It is possible to make new environmental conditions with specific conditions specified in order to evaluate the design of a product However only the pre defined NFRC 100 2010 shall be used for NFRC rating purposes 5 3 2 Coatings The location of coatings on a glass layer can affect the center of glazing U factor and therefore the whole product calculation so it is important to specify the location correctly When using a glass entry from the WINDOW Glass Library if the coating is not on the correct surface the glass layer shall be flipped To flip a glass layer while on a glass layer in Edit mode click on the Flip checkbox and the glass surfaces will be flipped as indicated by the dashed line in the graphic display of the glazing system azing System Library ID 3 Mame Double Low e Air Layers 2 a Tilt 90 IG Height 1000 01 mm Coating is on De NFRC 100 2010 IG width 1000 01 mm the outside of anedon the glass layer C t ommen 1 9 Overall thickness 21 OO mm Mode ID Hame Mode Thick Flip Tol Aaoll Asol Tvis Ayisl Avise Tir E E2 Cond Glass 17 H 925 CMFTIR_3 AFG 3 0 J 0496 0 395 0 331 0 780 0 126 0158 0 000 0 033 0 840 1 000 Gapi 1 Ar 27 L Glass 2 eR 103 CLEAR_B DAT 6 0 CI o0771 0070 0070 0884 0 080 0 080 0 000 0 840 0 840 1 000 Click on the Flip checkbox and the glass layer will be flipped so that th
110. C SHGC 0 and 1 and VT 0 and 1 cases in the Window Library as explained in Chapter 7 of this manual H W6 3 Glazing System Library C Users Public LBNL WINDOW6 w6 mdb File Edit Libraries Record Tools View Help i Fa e Z M4 gt Dl a hi oF Glazing Syster Library List Cale F3 ID 2 Name Double Clear Air New Layers pe Tilt 30 IG Height 1000 01 mm Copy Environment NERC 100 2010 1G Width 1000 01 mm Delete Comment EE Save Overall thickness 24 000 mm Mode aa Report ID Name Mode Thick Flip Tsol Rsa Asale Twis Ayvisl Awiz2 Tir E E2 Cond Glass 7 103 CLEAR_6 DAT 60 CI o0o 771 0070 0 070 0 884 0 080 0 080 0000 0 840 0 840 1 000 Gapl 1 Ait 12 0 LJ Glass 2 ee 103 CLEAR_6 DAT 60 Lor 0070 0 070 0884 0 080 0 080 0000 0 840 0 840 1 000 The center of glazing Solar The center of glazing Heat Gain Coefficient SHGCe Visible Transmittance Vtc Center of Glass Results Temperature Data Optical Data Angular Data Color Froperties Ufactor SC SHEL Rel Ht Gain Katt Gap 1 Keff wi fre F Wi rn wi fmm E Wi mF 2 6990 0 8092 0 7040 Aad 0 0638 0 0638 Figure 5 11 The center of glazing SHGC and VT are calculated in the WINDOW Glazing System Library THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 5 11 5 4 Solar Heat Gain Coefficient and Visible Transmittance 5 MODELING CENTER OF GLAZING WITH WINDOW 5 12 June 2013 THERME6 3 WINDOW6 3 NFRC Simulation Manual 6 MODELING FRAME AND ED
111. Conditions 6 MODELING FRAME AND EDGE HEAT TRANSFER WITH THERM When boundary conditions are generated for a model the program keeps them in the model until they are regenerated If the boundary conditions are regenerated the program will display a dialog box with three choices for how the program should generate them as shown below Generating Boundary Conditions xj When generating the new Boundary Conditions Use the same library type as any existing or deleted boundary conditions but assign new emissivittes based on material properties Use all of the properties of any existing or deleted boundary conditions ignore all of the properties of any exsting or deleted boundary conditions Cancel Figure 6 28 The dialog box displayed when boundary conditions are regenerated In general pick the first option in Generating Boundary Conditions dialog box which will pick up the emissivities of the materials in the model However do not select this option if you have edited the emissivities of material boundary conditions such as frame cavities by hand All the boundary conditions can be deleted by deleting one boundary segment Boundary conditions and U factor tags are stored in libraries and new entries can be defined for both using the Libraries menu choice See Section 6 2 Assigning Boundary Condition Definitions in the THERM User s Manual for more detailed information Occasionally THERM loses track
112. Conditions but assign new U factor Surface tags as follows Interior Frame from the midpoint to the top sightline set the U factor Surface tag to Frame from midpoint to the bottom sightline and the entire bottom glass assign the U factor Surface tag to None Interior Glazing System for the first 63 5 mm of the top glazing system set the U factor Surface tag to Edge and the remainder of the glazing system to None For the entire bottom glass assign the U factor Surface tag to None Exterior Frame from the midpoint to the top sightline assign the U factor Surface tag to SHGC Exterior from midpoint to the bottom sightline assign the U factor Surface tag to None Exterior Glazing System set the U factor Surface to None THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 97 8 SPECIAL CASES 8 9 Site Built fenestration products Curtain Walls Window Walls and Sloped Glazing Right Jamb Exterior Interior 150 mm 6 0 inches BC lt glazing system gt U factor Inside Film Radiation Model AutoEnclosure U factor tag None BC NFRC 10 20100 Exterior Radiation Model Blackbody U factor tag None 63 5 mm BC lt glazing system gt U factor Inside Film 2 5 inches Radiation Model AutoEnclosure U factor tag Edge a BC Interior lt frame type gt Convection only Radiation Model AutoEnclosure U factor tag Frame BC NFRC 100 2010 Exte
113. Create Link option e the eyedropper tool will appear click on the glazing cavity the polygon to link to and the other cavity will turn gray and have the same name as the glazing system cavity e The linked cavity will turn gray Libraries Options Calculation Window Help Set Material F4 Set Boundary Condition F5 The width of these cavities is lt Material Library ShiFt F4 5 mm so they eile Condition Library Ulich are not linked to Gas Library Shift F S eee the glazing Select Material Boundary Condition system cavity Glazing Systems F and are modeled UFactor Mames as frame cavities Create Link Remove Link Find the location in this cavity where the throat is lt or 5 mm Make that part The upper of the cavity a frame cavity is linked cavity and the area to the glazing of the cavity gt 5 mm cavity because link to the glazing the throat between them is gt 5mm These cavities are linked to the glazing system cavity because they are gt 5 mm wide See section 6 4 4 for more details about linking cavities Figure 8 146 Fill the cavity next to the venetian blind by linking it to the main glazing cavity THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 161 8 SPECIAL CASES 8 14 Venetian Blinds Between Glass Integral 6 Generate the Boundary Conditions The section of the warm side of the glazing system adjacent to the retracted venetian blind should be defined with a U fac
114. D 8 U factor Insi gt xi Bound Satta sample sill S ample GleSys ID 8 U factor Ins U Fact seca Edge Ce Boundary Temperature 21 0 C He 261 Wwm K Condition Library Radiation Model AutoE nclosure Emissivity 0 840 Shading system modifier More Blocking Surface sampfsill Sample GleSys ID 8 U factor Inside Film Boundary Conditions l Double click on a Default Boundary Conditior boundary condition segment to open the Boundary Click on Boundary Condition Library Ix Condition Type button to edit the sample sil Sample GleSys 10 8 U facdiing dialog box library Make sure the Model Comprehensive xl Cancel Radiation is set to ec C ti Automatic Enclosure seh ae New a7 T t 2 C Wer Model emperature var Delete Film Coefficient 2 614 wemeK D var Rename I Constant Heat Flux Color Flux 0 Wi fre var Save Lib W Radiation f Automatic Enclosure Model Save Lib As Manual Enclosure Model B Load Lib Black Body Radiation Ti ja C Ei i Protected View Factor fi Linear Hr 4596 Wm2 K Temperature 21 C 4 Radiation Effectiveness f bay I ara ldx dy 0 0 0 0 llen 0 0 Step 10 0 mm wih 0 0 63 5 0 0 E Eornstart Temperature Read at Temperature 21 C vyan Figure 6 27 Make sure that the interior boundary conditions have set to AutoEnclosure THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 6 33 6 5 Defining Boundary
115. DAT BRONZE_6 DAT CLEAR_3 DAT CLEAR_6 DAT GRAY_3 DAT SilA4g25LE_3ww bst AutBr30_Sww bst H 0_3 bsf H70 8_3 bsf NS20_3 bsf NS30_3 bsf H40_3 bsf SBr20_3ww bsf SBr35_3ww bsf SBr35 4_3ww bsf SBr50_3ww bsf NS10_3 bsf 20 ProductName Generic Bronze Glass Generic Bronze Glass Generic Clear Glass Generic Clear Glass Generic Grey Glass Silver 4G 25 Low E Autumn Bronze 30 Hilite 70 8 Mil Hilite 70 NightSky 20 NightSky 30 Hilite 40 Solar Bronze 20 Solar Bronze 35 4 Mil Solar Bronze 35 Solar Bronze 50 NightSky 10 iver 20 Manufacturer Generic Generic Generic Generic Generic Saint Gobain Solar Gard LLC Saint Gobain Solar Gard LLC Saint Gobain Solar Gard LLC Saint Gobain Solar Gard LLC Saint Gobain Solar Gard LLC Saint Gobain Solar Gard LLC Saint Gobain Solar Gard LLC Saint Gobain Solar Gard LLC Saint Gobain Solar Gard LLC Saint Gobain Solar Gard LLC Saint Gobain Solar Gard LLC Saint Gobain Solar Gard LLC Source OB vit a IGDB v11 4 IGDB v11 4 IGDB v11 4 IGDB v11 4 IGDB v16 3 IGDB v17 0 IGDB v16 3 IGDB v16 3 IGDB v17 4 IGDB v17 4 IGDB v17 4 IGDB v16 3 IGDB v16 3 IGDB v16 3 IGDB v16 3 IGDB v17 4 al Mode Color Thickness Tsol RAsoll Reol2 Tvis Avis Avis2 Tir noes aooo 0840 0 tFHrHHHHHHHHHRH HH HR OR Figure 5 2 WINDOW Glass Library mm 5 740 3 048 5715 3 124 3 023 3 023 3 277 3 404 3 251 3 251 3 276 3 023 3 023 3 073 3 023 3 251 maa 0 062 0 063 0 6
116. DOW Shading Layer Library THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 Venetian Venetian Venetian Venetian Venetian Venetian Venetian Venetian Venetian Venetian Venetian Venetian Venetian Fritted glass Fritted glass Venetian Venetian Fritted glass Fritted glass 8 200 8 SPECIAL CASES 8 16 Complex Glazing Database CGDB 2 Shading Layer Library Fritted Glass Records Highlight one of the fritted glass records and click on Detailed View to see the frit coverage and associated Glass Library records You will see that there are several glass layers referenced one for the substrate and two for the specular and diffuse optical data If these records are not already in the Glass Library they will automatically be imported when the Frit layer is imported into the Shading Layer Library If the frit coverage in the imported record does not correspond to the coverage of your product change the value and save the record Shading Layer Library ID 5001 Name Simulated Sandblast v 1086 70 00 Froduct Mame Translucent Frit Simulated Sandblast 1086 7 Manufacturer Wiacon Type Fittedgass The Glass substrate cannot be changed Frit coverage enter the appropriate value if it is different than the default from the CGDB Fritted glass The referenced Glass Library C U sers rdmitchell D ocuments My Dropbosinfic T raning E TE E E optical data files Fre Training for
117. E E N E sass aueenesa neat 5 1 E 119 ons sa a E PAE A E E E ee nee A E P A E 5 2 5 2 1 Updating Glass Library from the IGDB eeeeerereereeererereree 5 3 5 3 Glazing System Library Center of Glazing U factor eseese 5 4 53 1 Environmental COnditiOMS oxcic ates oan eae eaten 5 7 THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 Contents D2 C OUNO Eraka E A fete al OT 5 9 R EEA oid ene E E E E A ae rr nce rere 5 10 5 3 4 Laminated Glass Applied Films ee eee eeeeeeeneeeeneeeseeeeeeeeees 5 11 5 4 Solar Heat Gain Coefficient and Visible Transmittance s 5 11 7 TOTAL PRODUCT CALCULATIONS USING WINDOW 7 1 Tee We PVC EV LOWY AE E ttnn staan AEE 7 1 7 2 Frame and Edge U tactors from THERM asics aa 7 1 7 3 Center of Glazing U factors from WINDOW ee eeeeeseceseeeeeeeeseeeseeesneenes 7 2 7 4 Overall Product U factor SHGC VT and CR Calculations eee 7 3 7 4 1 Individual Product SHGC and VT SHGC 0 amp 1 VT 0 amp 1 7 6 74 2 sighthine Grouping Procedures rieni 7 9 7 4 3 Whole Product U factor With Dividers eeeeeeereeeererererere 7 12 TO Project Databases vs cessenssctisssicayosduiaseacentaustersiasuacedeayssamelasedasalaunsersiatacccasaiseaieloient 7 13 6 SPECIAL CASES spicssicctaci ica Race teeetece ice stacitee ete See Recerca aceasta 8 1 O LOVET O W anaa a a gai a Aaa uaa aetines pe ieadeeds 8 1 02 Menne RAS rnise nan e a a T 8 2 8 2 1 Modeling Meeting Rails seeeeee
118. Edge BC NFRC 100 2010 Exterior Radiation Model Blackbody U factor tag None BC lt glazing system gt U factor Inside Film Radiation Model AutoEnclosure U factor tag None Figure 8 95 Left Jamb Boundary Conditions leftjamb_boundary thm NOTE the THERM File option Use CR Model for Window Glazing System may be left checked since THERM will not calculate Condensation resistance for a cross section Type tagged Vertical Meeting Rail or Jamb THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 99 8 SPECIAL CASES 8 9 Site Built fenestration products Curtain Walls Window Walls and Sloped Glazing Modeling the Intermediate Horizontal as Head and Sill The horizontal frame cross section is drawn in exactly the same way as the intermediate vertical frame cross section including inserting the midpoint For this example the horizontal and vertical frames are identical so the same drawing is used Assign boundary conditions in the usual way and then assign new boundary condition U Factor Surface tags as follows for the head and sill For the Head Use the drawing for the intermediate horizontal In Therm File Properties File Properties set the Cross Section Type to Head Assign the Boundary Conditions as follows Interior Frame For the interior frame from the midpoint to the bottom sightline set the Boundary Condition to lt frame type gt Interior Convection Only and the U factor Surface ta
119. Ernigsivity 0 30 Therefore it is not necessary to check the emissivity of every frame cavity before the simulation because what is displayed are default values that are not particularly relevant The Temperatures are automatically calculated by the program side 2 Temperature 9 492 E Emissivity pon Note For some cavity types Keff Temperature and Emissivity data may not be conect until a simulation has been done The values shown are approximations Figure 6 7 Select the Frame Cavity choice from the Material Library that matches the emissivity for both sides of each frame 6 10 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 6 MODELING FRAME AND EDGE HEAT TRANSFER WITH THERM 6 3 Draw the Cross Sections THERM bases the convection in the frame cavity on rectangularizton of the cavity according to ISO 15099 specifications The current NFRC procedure is to break up cavities that are separated by a constriction or throat less than or equal to 5 mm 0 20 inches e A throat is defined as any place in a frame cavity where two walls two points or a wall and a point in the cavity are at or within 5 mm 0 20 inches of each other However if a frame cavity has a Nusselt number less than or equal to 1 20 before simulating it is not necessary to break it up into smaller cavities The Nusselt number can be displayed by double clicking on the frame cavity which displays the Properties dialog box The hor
120. F hgy 37 5 4 6 idee dy 267 3 245 4 len 377 8 Step 10 0 mm vt Ready vertical Divider NUM Zz Figure 8 23 A simulated divided lite in THERM THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 22 8 SPECIAL CASES 8 3 Dividers In THERM 1 Set the Cross Section Type to Vertical Divider 2 Import the glazing system for the divider which is the same glazing system as the rest of the product with the following settings Orientation Up Actual Cavity height 1000 mm 39 inches Sight line to bottom of glass height of the divider in this example it is 19 05 mm 0 75 inches Spacer height height of the divider in this example it is 19 05 mm 0 75 inches Edge of Glass Dimension 63 5 mm 2 5 inches Glazing System Height 150 mm 6 0 inches Draw spacer Not checked THERM 6 3 Untitled 2 15 x E File Edit View Draw Libraries Options Calculation Window Help x O amp L Set Material Fi Bz Eu Set Boundary Gondition ru Material Library Shift F4 Boundary Condition Library Shift F5 Gas Library Shift F6 Select Material Boundary Condition Step 1 Glazing Systems 5 Select Glazing Systems from the Libraries menu UFactor Names Greate Lint _ Orientation Up Glazing system width 18 796 mm Step 2 CR cavity height 1000 Pa Step 3 Select the appropriate glazing i Sight line to bottom of glass
121. F File Edit View Draw Libraries Options Calculation Window Help a x OSES ME Loe ia dqr epen E y SA vr 4 gt x y 392 0 66 6 dx dy 642 0 1193 5 len 1355 3 Step 10 0 mm A Ready Divider NUM 4 Figure 8 32 A true divided lite in THERM In THERM In this example it is easier to start by drawing the polgyons that represent the divider and then placing the glazing systems relative to those polygons 1 Set the Cross Section Type to Vertical Divider 2 Draw the divider polygons as shown in the figure below THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 31 8 SPECIAL CASES 8 3 Dividers THERM 6 3 TrueDividedLite THM Joj xj as File Edit View Draw Libraries Options Calculation Window Help l x gt W SiS boe st air bP aQaed amp F euj ay TET idx dy 5 1 44 5 len 45 3 Step 10 0 mm Ready E ivider M MUM Figure 8 33 In THERM draw the polygons for the divider elements that the glazing systems will fit into 3 Import the first glazing system in this case the top glazing system for the divider with the following settings Set the Locator in the appropriate location for where the glazing system will start in this example 3 175 mm 0 125 inches above the bottom of the divider Orientation Up Actual Cavity height 1000 mm 39 inches Sight line to bottom of glass height of the divider in this example it is 9 525 mm 0 375 inches Spacer height height
122. Fiberglass PE Resin z Use convection plus enclosure radiation Default Boundary Conditions f Use U factor values Use SHGC values Interior Boundary Condition Use convection plus enclosure radiation Extenor Boundary Condition Use existing BC from library select below NFRC 100 2070 Exterior Figure 8 4 Insert the first glazing system THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 4 8 SPECIAL CASES 8 2 Meeting Rails 4 Reposition the locator to the upper left corner for the 2 4 glazing system Step 4 Reposition the Locator in the upper left corner of the frame for the 2 glazing Figure 8 5 Reposition the Locator for the 2 4 glazing system 5 Insert the 24 glazing system setting the Orientation to Down and entering the correct values for Sight line to bottom of glass and Spacer height Insert Glazing System loj x Orientation Down Calculation Window Help la x Cance Pag ole E U 3mm cG Glazing system width 25 34 CR cavity height 1000 Step 7 Sight line to bottom of glass 119 430 Clicks on Add as P l additional glazing system Spacer height 9 7790 Edge of Glass Dimension 63 5 Glazing system height 1 KO Sight line to shade edge E Use nominal glass thickness Use CR Model for Window Glazing Systems SSS eee eae Gap Properties Default t Custom Gap 1 Keff 0 039206 Week Width 15 4 mm Step 6 Insert the 2 glazi
123. GE HEAT TRANSFER WITH THERM 6 1 Overview In order to calculate the total product U factor the U factor must be determined for the following components and then these values must be area weighted for the whole product Center of glazing values from WINDOW Frame and edge of glazing values from THERM The NFRC 100 Procedures for Determining Fenestration Product U factors is the definitive source for the methodology for calculating U factors and should be used for situations not covered in this manual In addition NFRC Technical Interpretations supplement the NFRC 100 document and these should also be consulted when questions arise 6 2 Cross Sections to be Modeled The fenestration product being modeled must be divided into the cross sections which completely define the heat transfer through the product THERM is used to calculate the U factor values for the edge of glazing as well as the frame components sill head jamb meeting rail and divider The operator type of the fenestration product as well as the configuration of each component of the frame will determine the number of cross sections that must be modeled Table 6 1 lists the minimum and maximum cross sections that must be modeled for each operator type and Figure 6 1 illustrates where the cross sections must be taken The maximum assumes that each frame cross section is unique and therefore must be modeled If there are some cross sections of the frame which are id
124. HERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 3 13 3 8 Infrared Properties of Glazing Materials Emittance 3 FENESTRATION HEAT TRANSFER BASICS Standard glass has an emittance of 0 84 over the long wavelength portion of the spectrum meaning that it emits 84 percent of the energy possible for an object at its temperature It also means that for long wave radiation where there is no transmittance striking the surface of the glass 84 percent is absorbed and only 16 percent is reflected By comparison low E glass coatings have an emittance as low as 0 04 This glazing would emit only 4 percent of the energy possible at its temperature and thus reflect 96 percent of the incident long wave infrared radiation 3 14 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 4 SUMMARY OF ALGORITHMS 4 1 THERM and WINDOW Algorithms This section is a brief overview of the calculational algorithms found in THERM and WINDOW Much more detailed documentation is available at http windows bl gov software and is referenced in the appropriate parts of this discussion The algorithms in both programs are based on ISO 15099 with the exceptions documented in Appendix A of this manual 4 1 1 WINDOW The WINDOW program calculates Center of glazing properties of a glazing system Total product area weighted properties based on previously calculated center of glazing properties frame edge of glazing divider and divider edge properties calc
125. IGDB v17 4 5 800 0 891 0 083 0 083 0 909 0 087 0 087 0 000 0 840 0 840 3526 records found 14709 Eurofloat6 EGS Eurofloat 6mm Euroglas GmbH IGDB v17 4 5 800 0 820 0 075 0 075 0 898 0 082 0 082 0 000 0 840 0 840 Import 14710 Eurofloat5 EGS Eurofloat Sram Euroglas GmbH IGDB v17 4 4800 0835 0 076 0 076 0 901 0 083 0 083 0 000 0840 0 840 14711 Eurofloat EGS Eurofloat 8mm Euroglas GmbH IGDB v17 4 7 800 0 791 0 073 0 073 0 892 0 082 0 082 0 000 0 840 0 840 Export 14712 Eurowhitel2 EGS Eurowhite 12mm Euroglas GmbH IGDB v17 4 11 800 0 869 0 081 0 081 0 905 0 086 0 086 0 000 0 840 0 840 Report 14713 EurowhitelO EGS Eurowhite 10mm Euroglas GmbH IGDB v17 4 9 800 0 876 0 082 0 082 0 906 0 086 0 086 0 000 0840 0 840 Print 30009 102 Vanceva4quamarine 9811 usr User IGDB User vL 6 374 0 737 0 069 0 069 0 787 0 074 0 074 0 000 0 840 0 840 7 NFRC only 4 gt x Mode NFRC SI NUM YW For Help press F1 The laminate has now been imported from the Optics user database to the WINDOW Glass Library It can now be used in the Glazing System Library to create a glazing system Figure 8 122 The laminate has now been added to the WINDOW Glass Library THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 130 8 SPECIAL CASES 8 12 Creating an Applied Film Layer in Optics for NFRC Certification 8 12 Creating an Applied Film Layer in Optics for NFRC Certification 8 12 1 Overview Glazing layers with applied films can be constructed using Optics f
126. Layer Library is imported into a working WINDOW database the associated Shade Material Records are also imported For example for the Venetian blind Shading Layer Library record below the associated record in the Shade Material Library is automatically imported and associated with the Shading Layer Shade Material Library C gt Users rdmitchel Documents My Dropbos nfreiT ramings B TE NFARC Training for Software Approval Complex Mame Product ame Manufacturer Source Mode Color Thickness Taol mm Shading Layer Library ESDF Material LENL example for Kleme coord p g BSDF Material Koester Retrolux Blind Woven Shade Material Woven Shade Generic User Name olin White Open Off white Slat Off white diffuse slat Genie IGDB User vl Product Name Slim White Venetian Blind Light Green Slat Light green slat Generic IGDB User wL Light Brown Slat Light brown slat Genetic IGOE User wL Manufacturer Fella i Red Slat Red slat Generic IGDB User wL Type Venetian blind horizontal Dark Blue Slat Dark blue slat Generic IGDE User wL a Reece 31109 White Venetian Blind Slat whit BSDF Material Name Manufacturer id White Wenetian Blind Slat vhite bet White Venetian Blind Slat Pella CODE White Venetian Blind Slat white bet White Yernetian Blind Slat Pella CODE White Venetian Blind Slat white bt White Venetian Blind Slat Pella CGODB Me 17109 white Venetian Blind Slat white bat White Venetian Blind Slat Pella CODE o100 0000 l 0 6F
127. Libraries Model the whole product using the Glazing System Frame and Divider components Figure 8 128 An example of a framed intermediate pane Section A is modeled for the Sill Jamb Section B is modeled for the Head and Section C is modeled as a Divider THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 141 8 SPECIAL CASES 8 13 Framed Intermediate Pane 8 13 2 THERM Modeling Details The THERM modeling is relatively straightforward with a few details to be aware of shown below The head and sill are modeled normally except that the extra frame for the intermediate pane is also modeled The sightline will remain defined as the highest interior point on the window door frame If the glazing system is gas filled any frame cavity opening into the glazing cavity must also be gas filled See 8 3 1 3 Dividers for information about creating gas filled frame cavity materials Example Sill Link spacer cavity to glazing system cavity above if appropriate Because this is a sealed unit the 5 mm rule for linking frame cavities and glazing cavities does not apply Therefore the cavities around and inside the spacer that are next to AN the glazing cavity are linked to that cavity See Section 6 4 4 Intermediate pane Frame for intermediate pane Figure 8 129 Example sill with framed intermediate pane THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 142 8 SPECIAL CASES 8 13 Framed Interme
128. Library ID H 26 Mame Sandblast Frit Layers E H Tilt 90 Il Height 1000 00 mm Environmental oa Conditions FPC 100 2004 IG width 1000 00 mm Comment Overall thickness 20 700 mm Mode E IL Name Mode Thick Flip Tal Aso Rolt Tvs Ayvisl Aviz Tir E Ez Cond 50 L O796 0062 0 063 0g88 0 065 0066 0000 0 840 O840 1 000 Gapi r 1 Ai 12 7 IE Glass 2 e 102 CLEAR_3 DAT 30 L o834 0 075 0075 0899 0 083 0 083 08 000 O840 0 840 1 000 Center of Glass Results Temperature Data Optical Data Angular Data Color Froperties Ufactor Rel Ht Gain Ket Gap 1 Keff Wi t m2 E Wma Wi fro K Wi fon B 2 7 16 465 0 0669 0 0669 Figure 8 186 Calculate the results for the glazing system 3 THERM Import the glazing system into THERM in the usual way A glazing system with a fritted layer does not have any different values in THERM than a normal glazing system i e a glazing system without a shading system 4 WINDOW Import the THERM files into the WINDOW Frame Library and then construct the whole product in the Window Library in the normal manner THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 198 8 SPECIAL CASES 8 16 Complex Glazing Database CGDB 8 16 Complex Glazing Database CGDB The Complex Glazing Database CGDB is provided by LBNL for modeling complex glazing products Over time more products will be added to the database as methodologies are developed to measure the properti
129. Library and the glazing system defined in Glazing System Library These steps are illustrated in more detail in the following discussion THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 163 8 SPECIAL CASES 8 14 Venetian Blinds Between Glass Integral In WINDOW 1 Shading Layer Library If the appropriate venetian blind product is not already in the Shading Layer Library import it from the Complex Glazing Database CGDB In the CGDB Shading Layer Library for Venetian blinds that are defined as Type Venetian not Type BSDF which are currently not allowed in NFRC certification there may be one or more definitions for the same Venetian blind product These different records will represent different geometries of the Venetian blind such as slat thickness width slat spacing and slat tilt If you are modeling the same Venetian blind product but with a different slat thickness width slat spacing or slat tilt you can make a new Shading Layer Library and change the slat geometry In this example the Venetian blind has three records in the CGDB Shading Layer Library representing three different slat tilts Closed 45 degrees and Open For NFRC certification the 45 degree geometry is not needed and therefore only the Closed and Open records are imported from the CGDB as shown in the figure below Shading Layer Library C gt U sers Public LEN LW IN DOW BwbYenetian mde ID Nam
130. Manual 6 MODELING FRAME AND EDGE HEAT TRANSFER WITH THERM 6 6 Calculating Results 6 6 5 Results When the calculation is finished the U factors shown in the figure below can be viewed using the Calculation Show U factor menu choice or the Show U factor toolbar button In addition the graphic display of the results can be controlled using either the Calculation Show Results menu choice or the Show Results toolbar button The U factors can be viewed for Projected X Projected Y Total Length Custom Length Projected in Glass Plane or Custom Rotation U factors are generally calculated as Project in Glass Plane but there are a few special cases where the Custom Frame Length feature must be used for an NFRC simulation See the following discussion in Section 6 6 6 Custom Frame Length for an example using Custom Frame Length The SHGC Exterior U factor is meaningless it is a result of the SHGC Exterior tag which is used by WINDOW to calculated the frame exterior wetted length for the ISO 15099 SHGC value ee A calculated as Projected in Glass Plane U factor delta T Length Wome K mm Rotation E Frame and Edge U factors SHGC Exterior 1 8081 E 42 8752 90 0 Projected in Glass Plane are reported These values Frame f20008 foao faze7sa 800 i Frojected in Glass Plane E will be used by WINDOW y Edge Y 2 3444 39 0 63 5 90 0 Projected in Glass Plane to calculate the total product U fa
131. Orientation Down Actual Cavity height 1000 mm 39 inches Sight line to bottom of glass height of the divider in this example it is 9 525 mm 0 375 inches Spacer height height of the divider in this example it is 9 525 mm 0 375 inches Edge of Glass Dimension 63 5 mm 2 5 inches Glazing System Height 150 mm 6 0 inches Draw spacer Not checked Insert the glazing system as an Additional Glazing THERM 6 3 TrueDividedLite THM o x E File Edit view Draw Libraries Options Calculation Window Help o x Debs Bbo teterraQ4zg amp FEU 7 NFR 100 2010 Exterior m Insert Glazing System xj Cancel Orientation jji Glazing system width fez mm CRH cavity height foo mm Sight line to bottom of glass ja525 mm Spacer height 55 mm Edge of Glass Dimension a5 mm Click on the Add as additional glazing system radio button in the Insert Glazing System dialog box Glazing system height f FO mm Site line to shade edge 0 mm gnd glazing system ight lin E SAGAN wate x Use nominal glass thickness bottom of glass and Use CR Model for Window Glazing Systeme Spacer height to the Replace Existing Glazing System Gap Properties ___ appropriate values Add as additional glazing system i Default i Custom Gap 1 Keff 066900 Wink Cancel width 127 mm Spacer Draw spacer Single spacer for multiple glazings Material Fiberglass PE Resin Z
132. PPP E PPAR APE EERO ee E E Sony 2 Butyl Divided ASHRAE N A HA HA Class H 15 5 Res 3 Wood Divided ASHRAE Suspended HA HA Class3 H 15 9 Mex 4 Insul Divided ASHRAE Suspended HA HA Class4 H 15 5 n 5 AlunSuspended ASHRAE Suspended HA HA Class5 N 16 0 0 30 a 6 Vinyl Suspended ASHRAE A At MA HA Class H 16 0 0 30 DividerContoured THM Them YerticalDivider 1 953 1 832 N A 25 4 19 1 0 30 i _Advanced _ 8 DividerContouredGasFilled THI Therm Vertical Divider 1 803 1 799 N A a4 ist oa 9 records found 9 SimulatedDividedL ite THM Them YerticalDivider 2 531 Arra NAA 18 9 22 2 0 30 Saal Step 3 The selected records will be Em imported into the library Report Print For Help press Fl Mode NFR SI NUM SCRL g Figure 8 31 Import the THERM file into the WINDOW Divider Library 11 Use the new divider in the calculation of the complete product values in the main screen of WINDOW THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 30 8 SPECIAL CASES 8 3 Dividers 8 3 3 True Divided Lites The criteria for when dividers are modeled can be found in NFRC 100 Section 1 4 4 Simplifications to a Product Line The discussion below describes the methodologies in WINDOW and THERM for modeling dividers when that criteria is met A true divided lite means that the dividers have separate glazing systems between the divider elements as shown in the figure below THERM 6 3 TrueDividedLite THM 7 mife x L
133. Problem 1 Vinyl Fixed Window Sill BC Adiabatic U factor tag None Cross Section Type Sill Gravity Vector Down BC 3 mm Vinyl U factor Inside Film Radiation Model AutoEnclosure U factor tag None BC NFRC 100 2001 Exterior Radiation Model Blackbody U factor tag None BC 3 mm Vinyl U factor Inside Film Radiation Model AutoEnclosure U factor tag Edge Gravity ect x BC NFRC 100 2001 Exterior Radiation Model Blackbody U factor tag SHGC Exterior BC Adiabatic __4 U factor taa None U Factors ee xi U factor delta T Length wi fone K E mm Rotation SHGC Esteriar fi A032 39 0 47 6249 30 0 Projected in Glass Plane Frame 1 5998 39 0 47 625 30 0 Projected in Glass Plane Edge 21163 E 63 5 30 0 Projected In Glass Plane Error Energy Norm fis ia Export BC Interior Wood Vinyl Frame convection only Radiation Model AutoEnclosure U factor taq Frame 188 Figure 9 2 THERM cross section and U factor results for the sill cross section THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 9 5 9 2 Problem 1 Vinyl Fixed Window 9 SAMPLE PROBLEMS Jamb BC Adiabatic U factor tag None Modeling Assumptions Cross Section Type Jamb Gravity Vector Into the Screen Jambs are modeled without the Condensation Resistance Model Gravity vecta BC 3 mm Vinyl U factor Inside Film Radiation Model AutoEnclosure BC NFRC 100 2001 Exterior
134. Projected in Glass Plane Frame E 891 T 39 0 49 301 T 30 0 Projected in Glass Plane Edge 2 031 J 39 0 fi 30 177 30 0 Projected in Glass Plane 3 Export 2 Error Energy Horm 8 96 diane a Figure 9 21 THERM cross section and U factor results for Meeting Rail Cross Section 9 26 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 9 SAMPLE PROBLEMS 9 3 Problem 2 Aluminum Horizontal Slider Window 9 3 5 Total Product U Factor In WINDOW import the THERM cross sections into the Frame Library Window Library C Program Files LBNL WINDOW63 Aluminum Slider mdb i joj x File Edit Libraries Record Tools wiew Help Cold tS S tn dp Baen o l Frame Library C Program Files LBN CYN D Ow ES aluminum Slider mdb Frame Edge HF_O1 THM Therm Head 7 151 2 08 25 lt 0 30 H y_O1 THM Therm Head 5 115 2 120 0 30 Delete JF_O1 THM Therm Jamb 5 026 2 071 0 30 J _O1 THM Therm Jamb p az4 211 0 30 MA_O1 THM Therm Yerticaly 7 060 2 025 0 30 SF_01 THM Therm Sill 6 851 2 056 0 30 sv 01 THM Them Sill 6 07 21 4 0 30 SRS Detailed View Update Copy Wu Advanced T records found Import Export Report ddd Frint El For Help press F1 Mode NFRC sI uum 2 Figure 9 22 THERM files imported into the Frame Library In WINDOW create a record in the Window Library using the appropriate THERM files from the Frame Library and glazi
135. Report Dividers le eb Normal v 4 For Help press F1 Dei Name Skylight 3mm Generic Mode NFRE x Type Skylight x gt Width 1200 mm Height 1200 mm Area 1 440 m2 Tit 0 Environmental Conditions NFRC 100 2010 m M lt 4 neo Mi OF Z Total Window Results U factor 13 57206 W m2 K SHGC 0 66238 Detail YT 10 70174 CR 36 Detail Click on a component to display characteristics below Glazing System Name Skylight Double Giz bal gt ID 2 Ucenter 3 329 W m2 K Nlayers 2 Sc 0 879 Area 0 974 m2 SHGC 0 765 Edge area 0 267 m2 Vic 0 814 i Mode NFRC SI Num WY THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 Figure 9 39 Window Library record for the skylight 9 41 9 4 Problem 3 Flush Mount Skylight 9 SAMPLE PROBLEMS Table 9 20 Total product U factors Glazing Options Total Product U Factor 17 mm 0 669 overall thickness W m 2 C Btu hr ft F Clear Air Clear 3 57206 0 62908 9 4 6 Individual Product SHGC and VT using SHGC 0 amp 1 and VT 0 amp 1 The methodology for determining the Solar Heat Gain Coefficient SHGC and Visible Transmittance VT for products is outlined in NFRC 200 using values of SHGCo SHGC VTo and VTi These values are calculated in WINDOW for the best glazing option modeled with the highest frame and edge U factor frame as outlined in NFRC 200 Section 4 2 3
136. SPECIAL CASES 8 14 Venetian Blinds Between Glass Integral BC Adiabatic U factor Tag None BC NFRC 100 2001 Exterior U factor Tag SHGC Exterior Insert a point on the exterior boundary condition at the sightline for the SHGC Exterior U factor taq BC NFRC 100 2001 Exterior U factor Tag None BC lt glazing system name gt U factor Inside Film Radiation Model AutoEnclosure U factor Tag None BC Adiabatic U factor Tag None Figure 8 158 Define the boundary conditions for the Head Non Retractable Open Venetian Blind cross section BC Interior lt frame type gt Convection only Radiation Model AutoEnclosure U factor Tag Frame BC lt glazing system name gt U factor Inside Film Radiation Model AutoEnclosure U factor Tag Frame BC lt glazing system name gt U factor Inside Film Radiation Model AutoEnclosure U factor Tag Edge 8 173 THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 SPECIAL CASES 8 14 Venetian Blinds Between Glass Integral BC Adiabatic U factor Tag None g lt glazing system name gt U factor Inside Film Radiation Model AutoEnclosure U factor Tag None BC lt glazing system name gt U factor Inside Film Radiation Model AutoEnclosure U factor Tag Edge BC lt glazing system name gt U factor Inside Film Radiation Model AutoEnclosure Un Tag Frame BC Interior lt frame type gt Convection only Radiation Mo
137. Section Type Sill Gravity Arrow Down Glazing System Up File Rotation 70 Clockwise BC Adiabatic U Factor Surface tag None U Factors ee xi U factor delta T Length wW mz F E mm R otatiori Frame 4 7604 33 0 43 0003 20 0 Projected in Glass Plane SHGC Eterior E 097 39 0 45 5854 20 0 Projected in Glass Plane Edge 2 5507 E 63 5 20 0 Projected in Glass Plane Error Energy Norm E334 Export Figure 9 36 THERM cross section and U factor results for the sill cross section THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 9 39 9 4 Problem 3 Flush Mount Skylight 9 SAMPLE PROBLEMS Jamb BC Adiabatic U Factor Surface tag None I 4 Skylight Jamb Gravity Yector jki Modeling Assumptions Cross Section Type Jamb Gravity Arrow Into the Screen Glazing System Up File Rotation None BC 3 mm Generic U factor Inside Film Radiation Model AutoEnclosure U Factor Surface tag None BC NFRC 100 2010 Exterior Radiation Model Blackbody U Factor Surface tag None BC 3 mm Generic U factor Inside Film Radiation Model AutoEnclosure U Factor Surface tag Edge BC Interior Wood Vinyl Frame convection only Radiation Model AutoEnclosure U Factor Surface tag Frame BC NFRC 100 2010 Exterior Radiation Model Blackbody U Factor Surface tag SHGC Exterior BC Adiabatic U Factor Surface tag None x U factor del
138. Sill elements THERM will not calculate the Condensation Resistance for a file with the Cross Section Type set to Jamb or Vertical Meeting Rail There are two methods for calculating the Condensation Resistance information in THERM which will be used in WINDOW to calculate the total Condensation Resistance of the product Check the Use CR Model for Window Glazing System checkbox when importing a glazing system OR In the Options menu Preferences choice THERM File Options tab check the Use CR Model for Glazing Systems as shown in the figure below SS llttt x Preferences Drawing Options Simulation Therm File Options Snap Settings m Mesh Control Quad Tree Mesh Parameter E MV Run Error Estimator Maximum Error Energy Norm fi 0 Maximum Iterations 3 V Use CR Model for Glazing Systems Figure 8 53 In Options Preferences Iherm File Options check the Use CR Model for Glazing Systems checkbox When the CR model has been turned on red boundary conditions will appear inside the glazing system and the following steps should be taken to simulate the file 1 Check the emissivities of these boundary conditions They should be the following Emissivity of the surrounding surface such as 0 84 for standard glass 0 90 for painted metal and most other frame materials 0 20 for mill finish metal and so forth 1 0 for the adiabatic open end of the glazing cavity 2 Simulate t
139. Simollied z Cavity Model sois j Gas Fija o a Emissivities Side 1 05 Side 2 0 3 Step 3 J Protected Frame Cavity NFAC 100 Argong Define the new Frame Cavity Material Type Frame Cavity Radiation Model Simplified Cavity Model ISO 15099 Gas Fill Gas from Gas Library Emissivities Irrelevant because they will be recalculated during th simulation Cancel Step 1 Click the New button to make a new Frame Cavity Material RS 8 8 hkx New Maternal name Step 2 Give the new material a unique name x Frame Cavity NFR 100 Argond5 Close Maternal Type Cancel Solid it Frame Cavity Glazing Cavity i External Radiation Enclosure E Delete Rename sold Properties Conducte isa Boyt bets Ermites ps Cavity Properties Radiation Model Simpified Cavity Model fiso15093 Gas Fill es ates T Emissivities Side 1 09 Side 2 09 Color Save Lib As Load Lib Elle Protected Figure 8 21 Import the gas mixture entries into the THERM Gas Library THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 20 8 SPECIAL CASES 8 3 Dividers 4 Use this new frame cavity material in the divider model cavities THERM 6 3 DividerContouredGasFilled THM Properties for Selected Polygon s Figure 8 22 Use the new Frame Cavity material to fill the divider cavities THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013
140. T recommended for most situations The Show Voids Overlaps from the View menu feature is also a good tool for visual inspection to find voids and overlapping polygons in a cross section In addition to the features that attempt to prevent the creation of bad geometry during the drawing process a number of error checks are performed when THERM calculates the boundary conditions in order to make sure the model geometry is correct For example when the boundary conditions are calculated THERM identifies all points within 0 1 mm 0 004 inches and 0 01 mm 0 0004 inches of each other points closer together than 0 01 mm are automatically merged A message box appears saying that there are points closer than the program tolerance as shown in Figure 6 27 In general select the option Automatically adjust points within tolerance option in which case THERM willl fix all of the points automatically This now works even for models with thin films in glazing systems If you are unsure about whether to let the program adjust the points automatically select the Mark the points but don t adjust them option which causes THERM to draw red circles in the problem areas Then you can examine all the circled points and fix them if appropriate or regenerate the boundary conditions and let the program automatically adjust them If the marked points are actual details in the drawing that need to be kept they do not have to be fixed although they might cause meshin
141. THERM 6 3 WINDOW 6 3 NFRC Simulation Manual Lawrence Berkeley National Laboratory June 2013 DISCLAIMER This document was prepared as an account of work sponsored by the United States Government While this document is believed to contain correct information neither the United States Government nor any agency thereof nor The Regents of the University of California nor any of their employees makes any warranty express or implied or assumes any legal responsibility for the accuracy completeness or usefulness of any information apparatus product or process disclosed or represents that its use would not infringe privately owned rights Reference herein to any specific commercial product process or service by its trade name trademark manufacturer or otherwise does not necessarily constitute or imply its endorsement recommendation or favoring by the United States Government or any agency thereof or The Regents of the University of California The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof or The Regents of the University of California Ernest Orlando Lawrence Berkeley National Laboratory is an equal opportunity employer LBNL 48255 THERM 6 3 WINDOW 6 3 NFRC Simulation Manual Robin Mitchell Christian Kohler Dragan Curcija Ling Zhu Simon Vidanovic Stephen Czarnecki and Dariush Arasteh Windows and Daylighting Group B
142. THERM6 3 WINDOW6 3 NFRC Simulation Manual 9 SAMPLE PROBLEMS 9 4 Problem 3 Flush Mount Skylight 9 4 Problem 3 Flush Mount Skylight 9 4 1 Description Window Type Skylight Overall Size Width 1200 mm Height 1200 mm Frame Material Wood Glazing System Double glazing 17 0 mm 0 669 overall I G thickness Both the inboard and outboard lites are generic 3 mm clear glass The glazing cavity is air filled Spacer Type Aluminum folded spacer Glazing Method Butyl rubber sealant Dividers N A Cross Sections See Section 9 4 7 for drawings of this product 9 4 2 Glazing Matrix The following table shows the glazing matrix that is to be simulated for the skylight Table 9 16 Matrix of glazing options for the skylight Glazing Options rae mm 0 669 overall thickness Grid a Clear 3mm Air Clear 3mm Generic THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 9 35 9 4 Problem 3 Flush Mount Skylight 9 SAMPLE PROBLEMS 9 4 3 Center of glazing Modeling WINDOW In WINDOW create a record for the glazing system using generic 3 mm clear glass for both lites and a 10 9 mm 0 429 air space air filled Make sure to set the Tilt to 20 The following figure shows the WINDOW Glazing System Library for this glazing system se Glazing System Library C Program Files LBNL WINDOW63 Sk light mdb l oO x File Edit Libraries Record Tools View Help Cae te O S SBle hdr wl Bo emi OF 2
143. The geometry of the cross section in Figure 8 80 would be used for the final THERM run and the conductivity of the materials used to define the bolt would be changed to the value derived from the methodology explained in this section The geometry in Figure 8 79 is drawn only to obtain the conductivity values for calculating the conductivity of this averaged material Figure 8 78 THERM cross section where the bolt occurs curtain wall bolt thm THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 80 8 SPECIAL CASES 8 8 Non Continuous Thermal Bridge Elements Figure 8 79 shows the conductivity values for the four materials that must be obtained for the calculation Material 1 and 4 are air cavities and the conductivity is assumed to be 0 024 W m K k4 Air cavity k2 Aluminum k3 Vinyl k4 Air cavity 0 024 W m K 160 W m K 0 12 W m K 0 024 W m K Figure 8 79 Materials in the non bridging material cross section for which conductivities must be obtained Figure 8 80 shows the depths of each of the thermal bridging elements that are used in the Keff calculation j 7 d4 0 01411m d1 0 00392m d2 0 003175m 43 9 00586 m Figure 8 80 Material depths for the thermal bridging materials THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 81 8 SPECIAL CASES 8 8 Non Continuous Thermal Bridge Elements Table 8 1 shows the conductivity and depth values used to calculate the R for each non thermal bridging
144. The most common reason a component is not saved is that its filename already exists in the IGDB or user database In this case Optics assumes that the component layer information is already available and does not need to be saved again 8 12 4 6 Renaming a Layer To rename a layer with an applied film Select the layer you want to rename by clicking on a layer button Choose menu option Edit Rename filename or Right click on the layer button to display the pop up menu and select item Rename filename Enter a new filename and click OK If you want to save the layer under the new name save it to the user database see Saving Layers to the User Database You could also achieve the same result by using the File Save As menu option to rename and save the layer in one operation THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 140 8 SPECIAL CASES 8 13 Framed Intermediate Pane 8 13 Framed Intermediate Pane 8 13 1 Overview For a product that has an intermediate pane with it s own frame the modeling steps are as follows In WINDOW Create the glazing system including the intermediate pane In THERM Model the head sill and jamb sections including the intermediate pane and frame using the glazing system created in WINDOW Model caming if applicable as shown in the Dividers section 8 3 4 of this manual In WINDOW Import the THERM cross sections into the Frame and Divider if modeling caming
145. U factor SHGC and VT values 9 2 1 Description Window Type Overall Size Frame Material Glazing System Spacer Type Glazing Method Dividers Cross Sections Fixed picture window Width 1200 mm Height 1500 mm PVC frame and stop with a wall thickness of 3 175 mm 0 125 The same geometry can be used for the head jambs and sill Double glazing 19 05 mm 0 750 overall I G thickness The outboard lite is double strength clear glass 3 277 mm 0 129 thick The inboard lite is double strength clear glass with a PPG Sungate100 Low E coating on surface three The glazing cavity is air filled 12 5 mm 0 492 thick Intercept spacer with PIB primary seal and hot melt butyl secondary seal Foam rubber tape 3 175 mm 0 125 thick Aluminum grille pattern painted white The grille pattern for the window is three by four and is between the glass See Section 9 2 7 for drawings of this product 9 2 2 Glazing Matrix The window is offered by the manufacturer both with and without dividers The drawings indicate that there is less than 3 0 mm 0 118 between the glass and the divider so the glazing matrix must include both a case with and without dividers 9 2 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 9 SAMPLE PROBLEMS 9 2 Problem 1 Vinyl Fixed Window 9 2 3 Center of glazing Modeling WINDOW Model the glazing system in WINDOW with double strength clear glass a 12 5 mm 0 492 air
146. Units Fenestration product manufacturers have some flexibility to reduce heat transfer by selecting the best gap width between two or more glazings The air space between two pieces of glass reaches its optimum insulating value at about 1 2 inch 12 mm thickness when filled with air or argon As the gap gets larger convection in the gap increases and slowly increases heat transfer Below 3 8 inch 9 mm conduction through the air gap increases and the U factor rises more rapidly Krypton gas has its optimum thickness at about 1 4 inch 6 mm so that if smaller air gaps are required for example in a three layer fenestration product whose overall exterior dimensions are limited krypton may be the best selection although it is also more costly 2 6 6 Divided Lights Manufacturers have been struggling with the problem of many homeowners preference for traditional divided light fenestration products which have many small panes separated by thin bars called muntins With single pane glass true divided lights actually improved the thermal performance of the fenestration product because the wood muntins had a higher insulating value than the glass Some manufacturers have introduced true divided light insulated units in which traditional looking muntins hold small individual insulated panes However these are expensive and difficult to fabricate with insulated glass and have greater thermal losses due to the number of edges which now have
147. WINDOW to be able to calculate the result For example if there are no CR results for a Sill or Head THERM file modeled in a window with a 90 tilt then WINDOW will not calculate a whole product CR value because the needed CR temperature data does not exist A message shown below will indicate which cross sections are missing the CR data Information Warning Window 2 The following Therm files do not contain current simulation results required for CA calculation Head THM Sill THM CR Data will not be available unless you resimulate the Therm files with a current version af Therm T Don t show this message again O x ss W6 Frame Library C Program Files LBNL WINDOW63 w6 mdb File Edit Libraries Record Tools view Help Cees SB S Bli hero nl HBa om ot Z K Frame Library List ID 5 Therm Name sample sill THM New Source Therm x Type sil Copy Filename S amplessample sill THM Browse __Detete UVALUES Save Frame 2 007 W m2 K Edge Correlation Edge of Glass 2 344 W m2 K m GLAZING SYSTEM Width 26 5 mm Center of Glass U value 1 934 W m2 K FRAME Projected Frame Dimension 42 9 mm Material Abs 0 300 Color ia Wetted Length 55 6 mm e m Condensation Resistance based on Therm CR simulation 30 RH 50 RH 70 RH Overall Frame 0 004 0 023 0 062 97 0 Edge 0 028 0 202 0
148. ZING WITH WINDOW 5 3 Glazing System Library Center of Glazing U factor H W6 3 Glazing System Library C Users Public LBNL WINDOW6 w6 mdb File Edit Libraries Record Tools View Help b Ga m iM 4 gt DI a emi OF Glazing System Library List Calc F5 ID H 2 Hame Double Clear Aur H Layers E B Tilt g0 IG Height 1000 01 mm Environmental RA Condition NFR 100 2010 IG Width 1000 00 mm Comment Overall thickness 24 000 mm Mode ID Name Mode Thick Flip Tol Roll Rsole Twis Ayisl Avis2 Tir E1 E2 Cond Glass 1 ee 103 CLEAR_6 DAT 6 0 J O771 0070 0 070 0884 0 080 0 080 0 000 0 840 0 840 1 000 Gapi F 1 At 120 LI Glass 2 ee 103 CLEAR_6 DAT 60 LJ O771 0070 0 070 0 884 0 080 0 080 0 000 0 840 0 840 1 000 Center of Glass Results Temperature Data Optical Data Angular Data Color Properties Ufactor SC SHEL Rel Ht Gain Gap 1 Kett Wi fre F Wim Wi rn E 2 6990 0 8092 0 7040 N 0 0638 For NFRC certification calculations of SHGC When the glass and gap layers have been and VT glass layers defined click on the Calc button and the from the Glass Library center of glazing U factor as well as other with a in the Mode field results will be displayed in the Results shall be used The section at the bottom of the screen This indicates that the record value is used when the glazing system is is approved for NFRC imported into THERM simulations Figure 5 4 Calculating results in the Glazing Sys
149. a Tvs Avil Ayise Tir E E2 Cond 102 CLEAR_3 DAT 30 o8s4 0075 0075 0 699 0 083 0 083 0 000 0 840 O840 1 000 1 Air 127 L Shade or fit ery 102 CLEAR 3 DAT 30 loss4 0 075 0075 0899 0083 0 083 0000 0 840 0 840 1 000 Figure 8 184 Select Shade or frit to see the Shading Layer Library records e Click on the Double arrow button to see the Shading Layer Library and select the appropriate Fritted glass record Glazing System Library ID 26 Hame Sandblast Frit H Layers 2 E Tilt g0 IG Height 1000 01 mm Environmental GAI Condon MFRC 100 2004 IG Width 1000 00 mn Comment Select Overall thickness 1 6 300 Cancel Find ID 19 records found ID Product ame 10 Venetian C30 11 Venetian OO 12 Venetian O45 13 Venetian O90 17 Wi hite Frit Slim White YE Closed Slim White Venetian Blind Slim White Oper Slim White Yenetian Blind WOK Viraspan T M Medium Gray W 945 30 WiraspaniT M Ceramic Frit Mediurn Gray M 94 St aT oe er Bon Simulated Sandblast 10861 70 Translucent Frit Simulated Sandblas t W 1086 704 a9 Clear Frit no pigment F F Ufactor Figure 8 185 Click on the double arrow to show and select the layers in the Shading Layer Library THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 197 8 SPECIAL CASES 8 15 Frits e Click the Calc button to calculate the center of glass properties for this glazing system Glazing System
150. able amount of solar gain 3 Low transmission Low E These Low E products are often referred to as sputtered or soft coat due to the glass coating process Note Moderate solar gain Low E products are also sputtered coatings This type of Low E product sometimes called spectrally selective Low E glass reduces heat loss in winter but also reduces heat gain in summer Compared to most tinted and reflective glazings this Low E glass provides a higher level of visible light transmission for a given amount of solar heat reduction The type and quality of Low E coating will affect not only the U factor but also the transmittance and solar heat gain coefficient of a glass All these properties U factor VT and SHGC need to be taken into consideration in characterizing a particular glazing product THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 2 11 2 6 Improved Glazing Products 2 FENESTRATION PRODUCTS 0 9 Idealized transmittance I of a spectrally selective 0 8 R E glazing designed for low z z solar heat gain Visible T 07 R light is transmitted and Solar i 23 9 C 75 F near infrared solar 0 6 Spectrum blackbody radiation is reflected a suitable for a warm Y i imat 0 5 a climate ha S 0 4 Human eye u 2mm dealized transmittance Co response M of a low E glazing _ designed for high solar S 0 5 heat gain Visible light and 9 1 near infrared solar A O 2 i radiation is transmitted H l Far infrar
151. act of Glazing Type and Spacers on Condensation 3 8 3 9 2 COndensa HOM Resistant e joist eet se ttc ee ite cae alee 3 9 D0 0 UTA OOT C ONCENS ATION reisseri E 3 9 3 5 4 Condensation Between GlaZings ossein 3 9 copa ab I al 6 g Rmeen mere se merme ste tere hae oan Pe UOC OORT rete ee ern nn tree ay tera ee rene 3 10 3 7 Solar Properties of Glazing M terialS erisin E 3 10 Ik TANSAN E 54 ated ssracessatcauesascenliege AE NA 3 11 Dil 2 REECE orana a E A seated et aetaae 3 12 ITs A DSO PANCE nie E eee eae 3 13 3 8 Infrared Properties of Glazing Materials Emittance eeeeeeeereerers 3 13 4 SUMMARY OF ALGORITHMG ccsscssssssssessesseesseessseseesseesseeseeesses 4 1 41 THERM and WINDOW Algorithms ciinei e S 4 1 E bL WINDOW neie R E T 4 1 Adee TAR ME RIVE icii a R T ES 4 1 4 2 WINDOW Computational Method cece eeeeeeeseeeeseeeeseeceaneceseeceeceseaeeseaneeaees 4 1 4 3 THERM Computational Methods eseceeseeeseeeeseeceneceaceceeeseeessneeeaees 4 4 AAs Total Product C alc ula HOns iazer a aa a AA 4 6 A lIa O a aa tasehatlh naanceiasaee ade oasSicaDasancles 4 6 4 4 2 Solar Heat Gain Coefficient GHGC cece eesceesseeceseeceneeeeeeeeaees 4 7 AA Se Visible TransmittanCe sascs sahcasceoavstessatenanchancteasera denis dPesagceodencuseoaiieece 4 7 4 4 4 Condensation Resistance a ceniciel sense attests cee ecc acetate 4 8 5 MODELING CENTER OF GLAZING WITH WINDOW 00 5 1 S ONEEN OWN era E A T
152. actor tag Frame BC Interior lt frame type gt Convection only Radiation Model AutoEnclosure U factor tag None BC NFRC 100 2010 Exterior iation M Black ee see ARDOAN BC lt glazing system gt U factor Inside Film Radiation Model AutoEnclosure U factor tag None Figure 8 97 Sill Boundary conditions sill_boundary thm It is a good idea at this point to verify the orientation and the direction of the gravity arrows of these sections In WINDOW Calculate these files and import into WINDOW Use the files to create the whole product in the Window Library as applicable THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 103 8 SPECIAL CASES 8 10 Garage Rolling Doors 8 10 Garage Rolling Doors Garage doors and rolling doors are modeled differently than window products because there are more opaque sections to be modeled in THERM The procedures for modeling doors are included in NFRC 100 and that document should be reviewed in detail before modeling any entry door systems As with all other product modeling all relevant cross sections must be modeled in THERM Detailed illustrations of sections elevations and model details as well as the area weighting methodology for calculating the whole product properties based on THERM results from of each cross section are defined in NERC 100 The information in this manual covers the specific modeling procedures for the THERM cross sections NFRC has de
153. ag SHGC Exterior Cross Section Type Head Gravity Vector Down BC NFRC 100 2010 Exterior Radiation Model Blackbody U factor tag None BC 3 mm CIG U factor Inside Film Radiation Model AutoEnclosure U factor tag None BC Adiabatic U factor tag None x U tactor delta T Length Wi me mm Rotation C Frame 4 9772 39 0 70 2442 30 0 Projected in Glass Plane SHGC Exterior 5 3332 39 0 70 2441 30 0 Projected in Glass Plane Edge A 311 39 0 63 5 30 0 Projected in Glass Plane 5 E t Error Energy Horm asz sie Figure 9 19 THERM cross section and U factor results for head vent cross section June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 9 24 9 SAMPLE PROBLEMS 9 3 Problem 2 Aluminum Horizontal Slider Window Head Fixed BC Adiabatic 1 U factor tag None LJ i BC Interior Thermally Broken Frame convection only Radiation Model AutoEnclosure U factor taq Frame BC NFRC 100 2010 Exterior Radiation Model Blackbody U factor tag SHGC Exterior BC 3 mm CIG U factor Inside Film Radiation Model AutoEnclosure Cross Section Type Head U factor tag Edge Gravity Vector Down BC NFRC 100 2010 Exterior Radiation Model Blackbody U factor tag None BC 3 mm CIG U factor Inside Film Radiation Model AutoEnclosure U factor tag None Sanam Adiabatic U factor tag None U Factors e xi U factor delta T ses Wi rn E Rotatior
154. aged matrix for Solar Band unchecked e Generate ful spectrally averaged matrix for Visible Band unchecked e Angular basis W6 quarter size e Solar Visible range Directional diffuse e FIR range Directional diffuse e ofsegments 5 THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 145 8 SPECIAL CASES 8 14 Venetian Blinds Between Glass Integral Leave Use Matrix method for specular systems unchecked It is not necessary to check Options Thermal Calos Optical Cales Optical Data Updates n Aa e a ut file or Write Optical calculation options e E Set both output EN E eee a j DN l Gang yer wd shading devs Solar Visible range Directional diffuse Solar Visible Solar band and Visible band can Hon a range and FIR FIR range lt lt y be left unchecked for NFRC ratings Write CSV output file range to these are only used to view results E Hof segments 5 Directional in the MatrixReader spreadsheet le a oso Set Spectral data to gt gt z Set of Condensed spectral data l segments to 5 Spectral data Condensed spectral data Set Number of visible bands to 5 ee Number of visible bands 5 Set Number of IR bands to 10 a Humber of IR bands 10 Angular basis W6 quarter size Set Angular basis to oo We6 standard basis Figure 8 133 Preferences settings for Optical Calcs Tab for Integral Venetian Blind THERM6 3 WINDOW6 3 NFRC Simula
155. ak material is poured in place polyurethane See drawings in Section 9 3 7 See drawings in Section 9 3 7 Section 9 3 7 contains the drawings for this example Aluminum painted white See drawing for dimensions Manufacturer provides standard 12 on center or less horizontal and vertical grid pattern for his products yy Double glazing 25 4 mm 1 overall I G thickness The manufacturer uses two different glass suppliers depending on the market availability and price factor The manufacturer uses clear and Low E coated glass from the same supplier Clear Glass from PPG or CIG with nominal thickness of 3 mm 4 mm 5 mm and 6mm Low E Glass from PPG Sungate100 or CIG LoE 145 with nominal thickness of 3 mm 4 mm 5 mm and 6mm Stainless steel spacer with PIB primary seal and silicone secondary seal PVC U channel Aluminum grille pattern painted white See drawing in Section 9 3 7 for dimensions The manufacturer provides standard 12 on center or less horizontal and vertical grid pattern for this product Based on the drawings and the glazing cavity thickness the dividers do not need to be modeled because the gap between the divider and the glass is greater than 3 0 mm 0 1187 See Section 9 3 7 for drawings of this product June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 9 SAMPLE PROBLEMS 9 3 Problem 2 Aluminum Horizontal Slider Window 9 3 2 Glazing Matrix The following table shows the glazin
156. al convection correlations For each frame material type there is a constant value of the convective surface heat transfer coefficient The radiation component is modeled explicitly through the use of a detailed view factor based radiation model This model assumes that the indoor environment has a uniform temperature and the emissivity of a black body s 1 0 while the appropriate emissivity is assigned to each frame and glass surface While the majority of surfaces have an emissivity of 0 9 metals like Aluminum have an emissivity of 0 2 On the outdoor side the convective portion of the boundary condition is specified as a constant dependent on the wind velocity The radiation component is modeled explicitly but under the simplified black body assumption i e each surface on the outdoor fenestration boundary has a perfect view of the outdoor environment with the view factor of 1 0 The convection and radiation in glazing and frame cavities is approximated through the use of an effective conductivity ker which assumes the gas to be an equivalent solid with the conductivity being equal to the base conductivity of the gas plus the convection and the radiation component added to the conductivity value The effective conductivity of the glazing is transferred from the WINDOW program while for frame cavities their value is calculated by the THERM program based on the geometry heat flow direction surface emissivities and temperatures The frame cavi
157. alculation Using Equation 4 1 from NFRC 200 Using Equation 4 1 from NFRC 200 and the data from Table 9 21 calculate the whole product SHGC from the SHGCo SHGCi and SHGCc SHGC SHGCo SHGCc SHGC SHGCo Without Dividers SHGC 0 002958 0 76504 0 864762 0 002958 0 66227 With Dividers lt 1 25 4mm modeled at 0 75 SHGC 0 005795 0 76504 0 0 781443 0 005795 0 59920 With Dividers gt 1 25 4mm modeled at 0 75 SHGC 0 008483 0 76504 0 702511 0 008490 0 53944 Table 9 22 Total product SHGC for the best glazing option Clear Air Clear Dividers Dividers lt 1 25 4 mm gt 1 25 4 mm Glazing Option No Dividers modeled at 0 75 modeled at 1 5 Clear Air Clear 0 66227 0 59920 0 53944 THERM6 3 WINDOWG6 3 NFRC Simulation Manual June 2013 9 43 9 4 Problem 3 Flush Mount Skylight 9 SAMPLE PROBLEMS VT Calculation Using Equation 4 2 from NFRC 200 Using Equation 4 2 from NFRC 200 and the data from Table 9 21 calculate the whole product VT from the VTo VT and VTc VT VTo VIc VTi VTo Without Dividers VT 0 0 0 81427 0 861802 0 0 0 7017 With Dividers lt 1 25 4mm modeled at 0 75 VT 0 0 0 81427 0 775647 0 0 0 6316 With Dividers gt 1 25 4mm modeled at 0 75 VT 0 0 0 81427 0 694027 0 0 0 5651 Table 9 23 Total product VT for the best glazing option Clear Air Clear Dividers Dividers lt 1
158. alog box e Orientation Down for the Head cross section e Cross Section Type Head Setting the Cross Section Type to the approriate value allows THERM to automatically insert a polygon in the correct place for the Dtop for Head Dbottom for Sill Dright for Right Jamb and Dleft for Left Jamb e Spacer Height 0 In this case it was easiest to set the spacer height to 0 and pull the sides of the glazing sysetm layers up to the frame on each side make sure Options Preferences Drawing Options has Allow Editing of IG Polygons checked Once the glazing system is inserted pull the glazing system layers up to meet the frame on each side Insert Glazing System Onentation Down Glazing system width 47 1104 mm CR cavity height 1000 mm Sight line to bottom of glass aasi mm Spacer height 38 911 mm Draw the Sight line to Edge of Glass Dimension 63 5 mm Venetian blind bottom of Glazing system height 1 FO mm anA Sight line to shade edge o mm Spacer height W Use nominal glass thickness Use CR Model for window Glazing Systems Sightline determined by Venetian blind hardware Edge of Venetian blind touches the blind hardware which defines the sightline so in this case the Sightline to shade edge value 0 Figure 8 170 Insert the glazing system with the Venetian blind THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 183 8 SPECIAL CASES 8 14 Venetian Blinds Between Glass I
159. ance between each node equals the inverse of the sum of the radiative and conductive convective heat transfer coefficients The temperature dependent conduction convection and effective radiation heat transfer coefficients for the outward facing and inward facing surfaces and for the gas filled gaps are calculated from the temperature distribution The heat transfer coefficients between the nodes within the solid materials simply depend on the conductivity of the materials where the materials are considered to be homogenous Conductive convective heat transfer coefficients are calculated based on empirical relationships The outdoor film coefficient depends on the wind speed and the direction from which the wind is blowing The indoor film coefficient is a function of the difference between the inward facing surface temperature the indoor temperature and the height of the fenestration product Gap heat transfer coefficients are computed from empirical equations for the Nusselt number The Nusselt number is a non dimensional quantity that relates the temperature difference between the surfaces bounding the gap and width height and thermophysical properties of the gap gas Fenestration product tilt is also accounted for in all conductive convective correlations The radiative energy flux leaving each surface is calculated from the Stephan Boltzmann law using the surface infrared hemispherical emissivity and temperature The net radiative flux between ra
160. anel with Glass Section Pa a HEAD JAMB AU 0 125 HEAD TO SLAB QDS 650 SEAL COMPRESSED TO 3 8 0 125 CLEARANCE GLASS SPACER 0 125 TEMPERED GLASS 0 125 TEMPERED GLASS 0 500 THICK O A OVERALL DIMENSION SLAB HEIGHT PLUS 2 7 16 0 125 CLEARANCE VENEER PANEL P DOOR SWEEP 0 440 THRESHOLD TO SLAB q r IN ee 5 750 ALUMINUM THRESHOLD YY Vo Figure 9 55 Half Panel with Glass Vertical Section THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 9 63 9 5 Problem 4 Door 9 SAMPLE PROBLEMS Half Panel with Glass Section GLASS SPACER 0 125 JAMB TO SLAB 0 125 4 502 TEMPERED GLASS 4 563 0 500 THICK O A 0 125 TEMPERED GLASS QDS 650 SEAL COMPRESSED TO 3 8 1 250 1 250 OVERALL DIMENSION SLAB WIDTH PLUS 1 3 4 UPPER HORIZONTAL CROSS SECTION Oaa 1 750 JAMB TO SLAB VENEER PANEL QDS 650 SEAL COMPRESSED TO 3 8 1 250 1 250 OVERALL DIMENSION SLAB WIDTH PLUS 1 3 4 LOWER HORIZONTAL CROSS SECTION Figure 9 56 Half Panel with Glass Horizontal Section 9 64 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 9 SAMPLE PROBLEMS 9 5 Problem 4 Door Sill Figure 9 57 Dimensioned drawing for the sill cross section THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 9 65 9 5 Problem 4 Door 9 SAMPLE PROBLEMS Jamb 4 563 Figure 9 58 Dimensioned drawing for the jamb cross section
161. apes a simplifying assumption is made that the 5 mm rule is not applied The space between the caming edge and the glass are modeled as frame cavities and the boundary of that cavity extends to the top and bottom of the caming component See the following examples for detailed descriptions In THERM In this example which represents an intermediate pane in an IG unit with caming it is easier to start by drawing the polgyons that represent the divider and then placing the glazing systems relative to those polygons 1 Set the Cross Section Type to Vertical Divider 2 Draw the caming polygons THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 39 8 SPECIAL CASES 8 3 Dividers 3 Insert the first glazing system in this case the top glazing system which is a triple glazed unit made in WINDOW for the divider with the following settings Set the Locator in the appropriate location for where the glazing system will start Orientation Up Actual Cavity height 1000 mm 39 inches Sight line to bottom of glass 0 Spacer height 0 Edge of Glass Dimension 63 5 mm 2 5 inches Glazing System Height 150 mm 6 0 inches Draw spacer Not checked Step 2 Insert the upper glazing system Step 1 Draw caming polygons Figure 8 41 Draw the caming polygons and insert the upper glazing system THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 40 8 SPECIAL CASES 8 3 Dividers 4 Insert
162. areas equals the total projected fenestration product area Figure 4 4 Schematic for whole product area weighting from the NFRC 100 document 440 Sune 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 5 MODELING CENTER OF GLAZING WITH WINDOW 5 1 Overview The WINDOW program calculates the center of glazing U factor U lt Solar Heat Gain Coefficient SHGC Visible Transmittance VT and Fading Resistance FR according to the following procedures NFRC 100 Procedure for Determining Fenestration Product Thermal Properties NFRC 200 Procedure for Determining Fenestration Product Solar Heat Gain Coefficients at Normal incidence NFRC 300 Procedure for Determining Solar Optical Properties of Simple Fenestration Product NFRC 500 Procedure for Determining Fenestration Product Condensation Resistance Values ISO 15099 Thermal Performance of Windows Doors and Shading Devices Detailed Calculations The WINDOW User s Manual WINDOW 6 3 User Manual for Analyzing Window Thermal Performance http windows lbl gov software contains detailed information about how to use the program and can be used to become familiar with the program before reading this manual For NFRC simulations the procedure for calculating the center of glazing U factor in WINDOW is Verify that the Glass Library entries are from the currently approved International Glazing Data Library associated with the Optics program the following website contains cu
163. aries Options Calculation Window Help x OSHS MB bos iaraa rope O vv 4 gt ky 36 6 12 5 dx dy 58 3 35 2 len 68 1 Step 10 0 mm Ue Ready vertical Divider NUM 4 Figure 8 28 Add the polygons for the simulated divided lite elements on either side of the glazing system THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 27 8 SPECIAL CASES 8 3 Dividers 7 Define the boundary conditions using the AutoEnclosure choice for the Radiation Model BC Adiabatic U factor tag None BC lt glazing system gt U factor Inside Film Radiation Model AutoEnclosure U factor taq None BC NFRC 100 2010 Exterior U factor tag None BC lt glazing system gt U factor Inside Film Radiation Model AutoEnclosure U factor tag Edge BC Interior lt frame type gt convection only ig BC NFRC 100 2010 Exterior Radiation Model AutoEnclosure U factor tag SHGC Exterior U factor tag Frame BC lt glazing system gt U factor Inside Film Radiation Model AutoEnclosure U factor tag Edge BC NFRC 100 2010 Exterior U factor tag None l BC lt glazing system gt U factor Inside Film Radiation Model AutoEnclosure U factor tag None BC Adiabatic U factor tag None Figure 8 29 Assign the boundary conditions THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 28 8 SPECIAL CASES 8 3 Dividers 8 Calculate the results THERM 6 3 SimulatedDividedLite THM 5 File E
164. ary All the environmental conditions referenced from the glazing systems and the Window Library entries Shading Layer Library Any records in the Shading Layer Library that are referenced from the glazing systems that are exported to the Project Database Shade Material Library Any shade material records that are referenced from the Shading Layer Library if Shading Layers are modeled in the exported glazing system Note that when you create a project database the program may display a message saying that some records already exists based on detecting duplicate record ID numbers and ask if you want to overwrite it as shown below 7 14 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 7 TOTAL PRODUCT CALCULATIONS USING WINDOW 7 5 Project Databases Be Window Record 1 already exists in ve CU sers Public t LBNL YA IND OW E Projec Do pou want to overnite it with the Mo current record Cancel Yes to All Figure 7 12 This message will always appear during an export This message will always appear for a New Project Database for Record 1 of the Environmental Conditions Library because the default blank database that the program writes into contains one default Environmental Conditions record For new project databases click the Yes button for overwriting existing records If you are importing records into an existing database you should determine what record ID numbers are already defined in the existing da
165. ase blic LBNLSLBNL Sharedy 63 CGDB 1 2 mdb Browse Venetian CD Advanced y Avoid creating duplicate records in export database by searching for identical records ID 2 3 4 p E i oo Yenetan Cod Venetian COO Cancel Yenetian DO Yenetian D45 Report Venetian O90 Print Wi hike Frit Clear Frit no pigment Slim White WB Closed Slim White Venetian Blind Slim White Opern Slim White Venetian Blind Figure 8 187 Browse to the CGDB database to import the frit records into the Shading Layer Library THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 199 8 SPECIAL CASES 8 16 Complex Glazing Database CGDB When the CGDB dialog box appears highlight the records to import and click the Select button or click the Select All button to import all the records in the CGDB file At this point for NFRC certification only the Fritted Glass and Venetian Blind products which can be either Type Venetian Blind or Type BSDF can be used so you may want to only select these products to import from the CGDB E C Users Public LBNL LBNL Shared W63 CGDB 1 2 mdb Teee Cancel Select all Clear selection Find ID 105 records found ID Mame Fagg Viraspan TM Medium Gray 0 945 30 engg B00 Simulated andblast 1086 70 Hexcel Screens 52 3 White Pearl W5 GreenScreen Eco 3 Pewter Platinum A5 Product ame Viraspan TM Ceramic Frit Medium Gray 948 30 Cove Transluce
166. at 0 75 at 1 5 SHGCo 0 00203 0 00495 0 00771 SHGC 0 86426 0 77823 0 69688 Ce S e THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 9 11 9 2 Problem 1 Vinyl Fixed Window 9 SAMPLE PROBLEMS SHGC Calculation Using Equation 4 1 from NFRC 200 Equation 4 1 from NFRC 200 is used to calculate the whole product SHGC from the SHGCo SHGCi and SHGCc SHGC SHGCo SHGCc SHGC SHGCo Where SHGCc center of glazing SHGC calculated in the Glazing System Library of WINDOW for the best glazing option 0 6079 in this example SHGCp total product SHGC values for a center of glazing SHGC of 0 0 calculated in the Window Library of WINDOW for the best glazing option SHGC total product SHGC values for a center of glazing SHGC of 1 0 calculated in the Window Library of WINDOW for the best glazing option SHGC total product SHGC calculated using Equation 4 1 The SHGC data from Table 9 5 is used with Equation 4 1 to determine total product SHGC as follows Without Dividers SHGC 0 00203 0 6079 0 86426 0 00203 0 5262 With Dividers lt 1 25 4mm modeled at 0 75 SHGC 0 00495 0 6079 0 77823 0 00495 0 4750 With Dividers gt 1 25 4mm modeled at 0 75 SHGC 0 00771 0 6079 0 69688 0 00771 0 4267 Table 9 6 Total product SHGC for the best glazing option Clear Air Low E Dividers Dividers lt 25 4 mm modeled at gt 25 4 mm modeled 19 5 mm lt 1 0 at 38
167. aterials such as in sweeps and seals THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 6 7 6 3 Draw the Cross Sections 6 MODELING FRAME AND EDGE HEAT TRANSFER WITH THERM 6 3 6 Frame Cavities For NFRC Simulations frame cavities are modeled using the ISO 15099 Cavity Model There are default items in the Material Library that can be used to model frame cavities Frame Cavity NFRC 100 to be used for all interior frame cavities Frame Cavity Slightly Ventilated NFRC 100 to be used for frame cavities open to the exterior See Section 6 3 7 Vented Exterior Cavities for a complete description of when to apply these cavities Material Definitions x Close Solid T ff Frame Easit Talasna Favit Blazing Lawit Ficlets C Betemal Aadatan Enclosure Rename sold Propeies Eonductieity fo Etur Emtesiwity fog Cavity Properties Load Lib Radiation Model Simpified gt Cavity Model sois GasFil Ar Emissivities Side 1 0 9 Side2 09 olor Save Lib As EEL EEE Protected Figure 6 5 Default frame cavity material for NFRC Simulations As shown in the figure above the Frame Cavity NFRC 100 material has the following characteristics Radiation Model Simplified Cavity Model ISO 15099 This cavity model is an implementation of the ISO 15099 standard and will cause THERM to automatically calculate the cavity wall temperatures emissivities and heat flow direction Gas Fill
168. atically created WINDOW does not recognize any U factor surface tags other than Edge Frame or None If you import door THERM files into WINDOW with U factor surface tags on the interior boundaries other than those values the WINDOW fields will not be correct If you intend to import these files into WINDOW use only the Edge Frame or None U factor surface tags for the THERM file interior boundary surfaces Because of this as well as the fact that WINDOW can not area weight the opaque portions of the door models total product values must be manually calculated externally by inputting the center of glazing results from WINDOW and the frame and edge results from THERM into a spreadsheet The table below shows the files for this example 9 48 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 9 SAMPLE PROBLEMS 9 5 Problem 4 Door Table 9 26 Files associated with the door example Cross Section Head Door Core Lock amp Hinge Jambs Sill Panel Edge Panel Core Door Lite Sill Base Case Door Lite Head Base Case Door Lite Jamb Base Case Door Lite Sill Option 1 Door Lite Head Option 1 Door Lite Jamb Option 1 Door Lite Sill Option 2 Door Lite Head Option 2 Door Lite Jamb Option 2 Door Lite Sill Option 3 Door Lite Head Option 3 Door Lite Jamb Option 3 Door Lite Sill Option 4 Door Lite Head Option 4 Door Lite Jamb Option 4 C e OOOO i osom er con es ioe ast anim ar oon es ieee ee er co
169. ation Thickness Pid Abs WWeim2 E W mz E mm mm Al w break ASHRAE N A 5 680 M Class M A B72 0 90 Al flush ASHAAE NA 3 970 MHA Class MA 57 2 0 50 Wood ASHAAE NA 2 270 MHA Class Mi 69 8 0 50 vinyl ASHRAE N A 1 700 MA Class MA 69 5 0 50 VenetianClased Head THM Therm Head 2 074 1 746 N A AF 114 8 0 30 ID Name Source Type YenetianClosed Jamb THM Therm Jamb 2 661 1 809 N A Af O76 0 30 YenetianLlosed Sill THM Therm Sill 1 853 N A Af o7 6 0 30 VenetianF med pen Head THM Therm Head 2 Fae 1 667 fy Ach 469 114 8 0 30 Venetian med U0 pen J amb THM Therm ooa VenetianFixedO pen Sill THM Them Sil se oan Figure 8 161 Import the THERM files into the WINDOW Frame Library mE 3 oo on e to Mm a E T Lo i m E Wi Lo 2 Window Library Construct the window using the THERM files in the Frame Library and the glazing system defined in Glazing System Library EH w63 Window Library C Users Public LBNL WINDOW6 w6Venetian mdb File Edit Libraries Record Tools View Help Cee SSB S Bti ud ro nl Baemii oF pile Calc FS Name Fixed penB Made NFRC New Type Fixed picture l width 1200 mm Rare Height 1500 mm save Area 1 800 m2 Report Tilt 90 Environmental Conditions Dividers NFRC 100 2010 Dividers Copy Display mode Normal Total window Results mT RRA EEN Ick on a component to display charactenstics below U factor 2117 Wiime K
170. ayer into the Shade Material Library In general this should be automatic and you should not have to manipulate the records in the Shade Material Library 3 Glazing System Library Define the glazing system with the venetian blind between two layers of glass In THERM 1 Frame Geometry Draw the frame geometry including Head Sill Jamb and Meeting Rail if appropriate 2 Glazing System Import the glazing system defined with the venetian blind vertical closed slats into the frame geometry 3 Boundary Conditions For Integral Venetian Blinds set Shading System Modifier to None 4 Simulate the model save the results THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 177 8 SPECIAL CASES 8 14 Venetian Blinds Between Glass Integral In WINDOW 5 Frame Library Import the THERM files into the Frame Library 6 Window Library Construct the window using the THERM files in the Frame Library and the glazing system defined in Glazing System Library These steps are illustrated in more detail in the following discussion In WINDOW 1 Shading Layer Library If the appropriate venetian blind product is not already in the Shading Layer Library import it from the Complex Glazing Database CGDB In the CGDB Shading Layer Library for Venetian blinds that are defined as Type Venetian and not Type BSDF there may be one or more definitions for the same Venetian blind product These different rec
171. brary C Program FilesSLENL WINDOWS Browse Window 6 Database Spacer height 12 557 Edge of Glass Dimension 63 5 m Glazing system height f Fo Site line to shade edge ja mn mm Step 1 Draw frame Use nominal glass thickness en 150 mm cross section Use CR Model for Window Glazing Systems Gap Properties _ 8 Exterior Boundary f Default f Custom Gap 1 Condition NFRC Keff 0063270 w 100 2010 Exterior widhi m Interior Boundary Condition Use convection plus enclosure radiation Spacer T Draw spacer Single spacer for multiple glazings Material Fiberglass PE Resin Default Boundary Conditions f Use U factor values Use SHGC values Extenor Boundary Condition Interior Boundary Condition Use existing BC from library select below Use convection plus enclosure radiation NFRC 100 2010 Exterior xy 8 403 2 146 dx dy 12 171 4 749 len 13 065 Step 0 394 inches Ready Figure 8 48 Insert the glazing system THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 49 8 SPECIAL CASES 8 4 Storm Windows 4 If necessary as in this example because there is a gap between the bottom of the glazing cavity and the frame create a separate polygon and use the Library gt Create Link feature to link the properties to the 2 glazing cavity In the example below the width of the inner gap is 50 800 mm and therefore is greater t
172. ceGlazingSystemThickness 5 Note it is all one word no spaces and it can go anywhere in the INI file If this line already exists but has some other value other than 5 change the value to 5 This represents the percentage tolerance between the frame and glazing system thickness Setting it to 5 makes the thickness tolerance checking 500 which should disable the WINDOW thickness tolerance checking and therefore allowing the program to perform a calculation with glazing systems of different thicknesses Location of W6 ini file The location of the W6 ini file will depend on your operating system For Microsoft Windows XP it is located in C Program Files LBNL Settings For Microsoft Windows 7 and Windows 8 it is located in C Users Public LBNL Settings Create the two glazing systems with the actual thicknesses between the glazing system and the storm window which will fit into the frame profiles that will be modeled in THERM In THERM Draw the frame components for the product in THERM Import the glazing systems with the actual gap widths into the appropriate frame profiles with the following settings Edge of Glass Dimension 63 5 mm 2 5 inch Glazing System Height 150 mm 6 0 inch Fill any air cavity between the bottom of the glazing system and the top of the frame profile as necessary and use the Library Create Link feature to link that air cavity to the glazing cavity Assign the boundary co
173. choice is the default and it creates and runs all the THERM files for the multiple glazing options defined in the base case file Simulate the current file base case only This choice is useful when setting up the base case file to make sure there are no geometry errors before running the entire multiple glazing options Create the glazing option files but do not perform the simulations This choice will cause the program to make individual THERM files for each of the glazing options associated with the base case file with either the Glazing System ID or Name appended on to the base case filename but it will not simulate the files These files can then be opened and simulated individually or simulated through the Calc Manager THERM 6 3 sample sill THM E loj x aS File Edit View Draw Libraries Options Calculation Window Help la x DeS2O Ss B boetlieatr rage d e F CulK Click on the Calc toolbar button select the Calculation Calculation menu choice or press the F9 shortcut key to start the calculation For a THERM file with multiple glazing options defined the Glazing Option Simulation dialog box is displayed Choose the appropriate option and click on OK For each glazing option THERM will automatically generate the appropriate boundary conditions for the interior of the profile next to the radiation enclosure Glazing Option Simulation x a s OF This file has glazing op
174. ckness f 6 996 mm Wire NFRC CMA Step 2 Select the glazing system created in WINDOW Insert Glazing System x Orientation Up v f Glazing system width fi 6 3 mm Sight line to bottom of glass 36 771 mm Edge of Glass Dimension 63 5 mm Glazing system height fi 50 mm e mm CR cavity height fi 000 mm Spacer height fi 1 585 mm Site line to shade edge fo e e e Use nominal glass thickness Use CR Model for Window Glazing Syste Gap Properties ee i Gap 1 e Keff 0 07299 Width 10 9 Default C Custom Spacer r r Draw spacer Single spacer for multiple glazings Material Fiberglass PE Resin x o Default Boundary Conditions Use U factor values C Use SHGC values Exterior Boundary Condition Use existing BC from library select below NFRC 100 2010 Exterior THERM6 3 WINDOW6 3 NFRC Simulation Manual Cancel Step 3 Insert the Skylight glazing system with the following settings Orientation Up CR cavity height 1000 mm Sight line to bottom of glass measured value Spacer height measured value Edge of Glass Dimension 63 5 mm 2 5 inches Glazing System Height 150 mm 6 0 inches Use CR Model for Window Glazing System not checked Draw spacer not checked Exterior Boundary Condition NFRC 100 2010 Exterior Interior Boundary Condition Use convection plus enclosure radiation Interior B
175. closure U factor tag Edge BC Interior lt frame gt convection only Radiation Model AutoEnclosure U factor tag Frame BC NFRC 100 2010 Exterior U factor tag SHGC Exterior BC lt glazing system gt U factor Inside Film Radiation Model AutoEnclosure U factor tag Edge BC NFRC 100 2010 Exterior U factor tag None BC lt glazing system gt U factor Inside Film Radiation Model AutoEnclosure U factor tag None BC Adiabatic U factor tag None Figure 8 37 Assign the boundary conditions THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 36 8 SPECIAL CASES 8 3 Dividers 7 Calculate the results THERM 6 3 TrueDividedLite THM Oj x L3 File Edit View Draw Libraries Options Calculation Window Help la x Ose Si Biboetla dr bLagege d Fleul Step 3 Click on the Calculation Show U factors menu choice to see the U factor results Step 1 Click on the Calc toolbar button to start the simulation Ix U factor delta T Length Wi fm B E mm Rotation Frame 3 7825 33 0 38 1 O01 90 0 Projected in Glass Plane Edge 3 0565 39 0 fi oF 90 0 Projected in Glass Plane SHGC Exterior 3 3998 35 0 38 1 30 0 Projected in Glass Plane model In this example isotherms are displayed The Show Eror Energy Norm 7 48 Export Results toolbar button will toggle 1 llah ox the results display on and off Step 2 When the simulation is finis
176. coatings were designed to have a high solar heat gain coefficient and a high visible transmittance to transmit the maximum amount of sunlight into the interior while reducing the U factor significantly A glazing designed to minimize summer heat gains but allow for some daylighting would allow visible light through but would block all other portions of the solar spectrum including ultraviolet light and near infrared as well as long wave heat radiated from outside objects such as paving and adjacent buildings as shown in Figure 2 3 These second generation Low E coatings were designed to reflect the solar near infrared thus reducing the total solar heat gain coefficient while maintaining high levels of light transmission Variations on this design modified coatings and or glazings can further reduce summer solar heat gain and control glare There are three basic types of Low E coatings available on the market today 1 High transmission Low E These Low E glass products are often referred to as pyrolitic or hard coat Low E glass due to the glass coating process The properties presented here are typical of a Low E glass product designed to reduce heat loss but admit solar gain 2 Moderate transmission Low E These Low E glass products are often referred to as sputtered or soft coat products due to the glass coating process Note Low solar gain Low E products are also sputtered coatings Such coatings reduce heat loss and let in a reason
177. ct up to the top of the glazing system outside inside Figure 8 136 Retractable Open Venetian Blind e Non Retractable Open Venetian blinds that are fixed at the bottom do not retract up the open state is defined as having the blind slats horizontal perpendicular to the plane of the glass outside inside Figure 8 137 Non Retractable Open Venetian Blind For Retractable Open two examples will be illustrated The venetian blind fully retracted inside a double glazed system The venetian blind fully retracted between an IGU and a third glazing layer such as but not limited to an add on panel For Non Retractable Open one example will be illustrated The venetian blind inside a double glazed system with the venetian blind slots in a horizontal open position THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 150 8 SPECIAL CASES 8 14 Venetian Blinds Between Glass Integral 8 14 1 1 Fully Retracted Open Venetian Blind Inside a Double Glazed System The following section discusses how to model a fully retracted venetian blind that has a stack of blind slats at the top of the glazing system The following figure shows the Head cross section for a venetian blind in the fully retracted position inside a double glazed system In this example only the Head section will be shown For Vertical Sliding windows where the lower sash contains avenetian blind between glass the lower sash por
178. ction 8 7 Doors Vehicular Access Garage Rolling Doors see Chapter 8 Section 8 12 Garage and Rolling Doors For these cases a spreadsheet can be used to calculate the total product area weighted values 7 2 Frame and Edge U factors from THERM As discussed in Section 6 6 7 Importing Results into WINDOW THERM files are imported into the WINDOW Frame and Divider Libraries in order to calculate the whole product values in WINDOW When the THERM files are imported into the WINDOW Frame and Divider Libraries they can be used in whole product calculations The Source field in the Frame Library indicates whether the files were imported from THERM as shown in the following figure fA W6 3 Frame Library C Users Public LBNL WINDOW6 w6 mdb File Edit Libraries Record Tools View Help EE Sa ellina Frame Library C Users PublicS LBNL Y WINDO W6Sw6 mdb Detailed View Frame Edge Edge Glazing Uvalue Uvalue Correlation Thickness Wm2 K W m2 K mm mm Al w break ASHRAE LBL 5 680 N A Class1 N A Al flush ASHRAE LBL 3 970 N A Class1 N A Wood ASHRAE LBL 2 270 N A Class1 N A Vinyl ASHRAE LBL 1 700 N A Class1 N A lss ID Ptd Name Source Copy Delete Find i 2 3 4 ID sample head THM 6 sample jamb THM 7 sample sill THM Advanced records found Import Export Report Print Figure 7 1 WINDOW Frame Library with records imported from THERM THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2
179. ction 8 for more details A graphic representation of the color of the glass Glass thickness Units mm SJ inches IP Solar transmittance of the glazing layer Solar reflectance of the glazing layer exterior facing side Solar reflectance of the glazing layer interior facing side Visible transmittance of the glazing layer Visible reflectance of the glazing layer exterior facing side Visible reflectance of the glazing layer interior facing side Thermal infrared longwave transmittance of the glazing layer Infrared longwave emittance of the glazing layer exterior facing side Infrared longwave emittance of the glazing layer interior facing side 5 2 1 Updating Glass Library from the IGDB The International Glazing Database IGDB is updated by LBNL approximately every three months These updates are available on the LBNL IGDB website http windowoptics lbl gov data igdb The WINDOW Glass Library should be updated when these IGDB releases occur There are detailed instructions on the website listed above about how to do this update THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 5 3 5 3 Glazing System Library Center of Glazing U factor 5 MODELING CENTER OF GLAZING WITH WINDOW 5 3 Glazing System Library Center of Glazing U factor The center of glazing U factor is determined in the WINDOW Glazing System Library A glazing system is created by specifying layers of glass from the Glass Library as well
180. ctor Error Energy Norm 6 72 Export Error Energy Norm must be less than 10 Use the Export button to generate a comma delimited file with the results Figure 6 36 U factor results from the Calculation Show U factors menu choice Local temperatures can be displayed at the cursor from the View Temperature at Cursor menu choice and average temperatures can be displayed with the tape measure from the Options Preferences menu Drawing Options tab check the Tape Measure Average Temperature checkbox THERM has a report which summarizes all the details of a THERM file including the polygon ID numbers for all cavities This report can be viewed and printed from the File Report menu choice THERM files THM can be saved without the detailed temperature data by selecting the Options Preferences menu going to the Simulation tab and unchecking Save Simulation results in THM files The THERM file will then contain only the geometry and boundary conditions used to run the simulation the U factor results and the report thus making the file much smaller THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 6 43 6 6 Calculating Results 6 MODELING FRAME AND EDGE HEAT TRANSFER WITH THERM 6 6 6 Custom Frame Length There is a case where THERM will not calculate the project frame length correctly This happens when a section of an adiabatic boundary overlaps a boundary with a U factor tag in the projected dimension over which
181. ctral Data Grid To view calculation warnings for the laminate data select the Warnings tab in the upper right part of the screen To see more information about the laminate choose menu option View View Details 8 11 3 8 Replace a Layer in a Laminate Replace a layer in a laminate in the same way as you would replace a layer ina glazing system you must respect the laminate building rules see 8 11 3 3 Add Layers to a Laminate You cannot insert layers into a laminate you must delete and add layers from the interior side of the laminate to modify the structure 8 11 3 9 Delete a Layer in a Laminate You can only delete the last interior side layer in a laminate To delete the last layer Select the last layer by clicking the layer button Choose the menu option Edit Delete Layer or Right click on the layer button to display the pop up menu and select Delete Layer 8 11 3 10 Save a Laminate To save a laminate to the user database Select the laminate by clicking on the Lamin layer button Click the Save button on the toolbar or Choose the menu option File Save filename or Right click the layer button to display the pop up menu and select Save filename Note To save the laminate under a different name choose the menu item Save As 8 11 3 11 Edit a Laminate To edit a laminate saved in the user database Make sure the Laminate tab is selected above the layer buttons
182. cts emit invisible thermal radiation with warmer objects emitting more than colder ones Hold your hand in front of an oven window and you will feel the radiant energy emitted by that warm surface Your hand also radiates heat to the oven window but since the window is warmer than your hand the net balance of radiant flow is toward your hand and it is warmed Now imagine holding your hand close to a single glazed window in winter The window surface is much colder than your hand Each surface emits radiant energy but since your hand is warmer it emits more toward the window than it gains and you feel a cooling effect Thus a cold glazing surface in a room chills everything else around it 3 3 4 U factor The U factor is the standard way to quantify insulating value It indicates the rate of heat flow through the fenestration product The U factor is the total heat transfer coefficient of the fenestration system in W m C Btu hr ft F which includes conductive convective and radiative heat transfer for a given set of environmental conditions It therefore represents the heat flow per hour in Watts Btu per hour through each square meter square foot of fenestration product for a 1 C 1 F temperature difference between the indoor and outdoor air temperature The smaller the U factor of a material the lower the rate of heat flow The total R value which measures thermal resistance is the reciprocal of the total U factor R 1 U The
183. d gt Radiation Model AutaEnclosure m assigned automatically by the program Emissivity 0 900 Library M Blocking Surface Figure 6 29 Standard boundary condition assignments for most models THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 6 35 6 5 Defining Boundary Conditions 6 MODELING FRAME AND EDGE HEAT TRANSFER WITH THERM Boundary Conditions for Nailing Flanges When modeling nailing flanges assign the NFRC Exterior boundary condition with U factor tag set to None to the portion of the nailing flange that is facing the exterior condition as shown in the figure below BC Adiabatic BC NFRC Exterior 2010 U factor tag None U factor tag None Figure 6 30 Boundary condition assignments for nailing flange 6 36 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 6 MODELING FRAME AND EDGE HEAT TRANSFER WITH THERM 6 5 Defining Boundary Conditions 6 5 3 Voids Overlaps and Bad Points In order to perform a simulation the geometry of the cross section must be correctly defined i e there must not be any voids overlapping polygons or points that cannot be resolved by THERM While drawing there are a number of features in THERM to help avoid creating voids overlapping polygons and bad points The Always Check for Overlapping Polygons feature in Options Preferences Drawing Options is the main tool used to avoid drawing overlaps and voids This option can be turned off but this is NO
184. d framing member BC Adiabatic U factor tag None Figure 8 100 End Stile Model THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 107 8 SPECIAL CASES 8 10 Garage Rolling Doors 8 10 1 4 Meeting Rail Door Panel Core Model The Meeting Rail Model is combined with the Door Panel Core Model as shown in the figure on the following page The meeting rail model shall include 63 5 mm 2 5 section of the each joining panel The projected dimension of the panel core section shall be equal to Height of the Panel 5 2 THERM File Properties Cross section Type Horizontal Meeting Rail Gravity Arrow Down THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 108 8 SPECIAL CASES 8 10 Garage Rolling Doors BC Adiabatic U factor tag None BC Interior lt frame type gt convection only Radiation Model AutoEnclosure U factor tag Core BC Adiabatic U factor tag None BC Interior lt frame type gt convection only Radiation Model AutoEnclosure U factor tag Core BC NFRC 100 2010 Exterior U factor tag SHGC Exterior BC Interior lt frame type gt convection only Radiation Model AutoEnclosure U factor tag Frame N Model the greater of 63 5 mm 2 5 or into 25 4 mm 1 of core material consistency from the meeting point of the panels Figure 8 101 Meeting Rail and Door Panel Core Model THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 109 8
185. d gray tints there is a greater reduction in visible light transmittance than there is in solar heat gain coefficient This can reduce glare by reducing the apparent brightness of the glass surface but it also reduces the amount of daylight entering the room To address the problem of reducing daylight with traditional tinted glazing glass manufacturers have developed new types of tinted glass that are spectrally selective They preferentially transmit the daylight portion of the solar spectrum but absorb the near infrared part of sunlight This is accomplished by adding special chemicals to the float glass process Like other tinted glass they are durable and can be used in both monolithic and multiple glazed fenestration product applications These glazings have a light blue or green THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 2 7 2 6 Improved Glazing Products 2 FENESTRATION PRODUCTS tint and have visible transmittance values higher than conventional bronze or gray tinted glass but have lower solar heat gain coefficients Because they are absorptive they are best used as the outside glazing ina double glazed unit They can also be combined with Low E coatings to enhance their performance further 2 6 2 Reflective Coatings and Films As the solar heat gain is lowered in single pane tinted glazings the visible light transmission drops even faster and there are practical limits on how low the solar heat gain can be made using
186. d the results specified in the NIBH E Calc Display Options menu choice TNN will be drawn on the model In this example isotherms are displayed The Show Results toolbar button will toaale the results disolav on and off x U Factors U Factor delta T Length Wi fre E C Rotation mm Edge 2 8048 39 0 1 ee 90 0 Projected in Glass Plane SHGC exterior 3 3783 33 0 1 3 0708 30 0 Projected in Glass Plane 39 0 Frame 3 1109 13 05 90 0 Projected in Glass Plane E t 6 Error Energy Mom 2 24 por a Figure 8 17 Calculate the results 8 Save the file using the File Save As menu choice THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 16 8 SPECIAL CASES 8 3 Dividers 9 Import the results to the WINDOW Divider Library as shown below See Section 4 7 3 Importing THERM files in the WINDOW User s Manual for more information about importing THERM files EH W6 3 Divider Library C Users Public LBNL WINDOW6 w6 mdb File Edit Libraries Record Tools View Help E Baemhit Ol 2 FT eR Divider Library C 4UsersPublicS LEN LA WIN DOW EE mdb Import Detailed View vpi b Alum Divided ASHRAc H 2 Butyl Divided ASHRAE N A 90 Woodi Divided ASARGE Suspe Step 1 From the WINDOW aoe rame Library click on the Update Format Therrn file A Window 5 or 6 Databaze Therm file ID Name Source Wa Copy r
187. d into the Shading Layer Library Producth ame Viraspan TM Ceramic Frit Medium Gray 948 30 Coverage Translucent Frit Simulated Sandblast 1086 0 Coverage 8 15 Frits Manufacturer ISO 15099 appendix ISO 15099 appendix ISO 15099 append ISO 15099 appendix ISO 15099 appendix ISO 15099 appendix ISO 15099 appendix ISO 15099 appendix ISO 15099 append ISO 15099 appendix ISO 15099 appendix ISO 15099 appendix ISO 15099 appendix Generic Generic Pella Pella Viracon Viracon Figure 8 182 The records selected from the CGDB will be imported into the WINDOW Shading Layer Library THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 Venetian Venetian Venetian Venetian Venetian Venetian Venetian Venetian Venetian Venetian Venetian Venetian Venetian Fritted glass Fritted glass Venetian Venetian Fritted glass Fritted glass 8 195 8 SPECIAL CASES 8 15 Frits Highlight one of the records and click on Detailed View to see the frit coverage and associated Glass Library records You will see that there are several glass layers referenced one for the substrate and two for the specular and diffuse optical data If these records are not already in the Glass Library they will automatically be imported when the Frit layer is imported into the Shading Layer Library If the frit coverage in the imported record does not correspond to the coverage of your product change the value and save the rec
188. d to do the door area weighting from the THERM files because the current version of WINDOW does not area weight doors In THERM the U factor Surface Tags can have any name and as many U factor Surface Tags can be defined as are needed to accurately describe the model See Section 6 2 4 Define U factor Surface Tags in the THERM User s Manual so define as many U factor Surface Tags as needed and name them descriptively SHGC CalculationWhen calculating the SHGC for the opaque components of a door using the ISO 15099 equation for frames see formula for SHGC below using an hou value of 30 W m C aens U SHGC surf es Boundary Conditions for Steel Skin Doors The following boundary conditions BC shall be applied when modeling doors containing a steel skin with either a non metal or wood edge or steel edge The appropriate BC shall be applied to applicable individual sections Non metal wood edge Wood Vinyl Steel edge Thermally Improved Chapter 9 contains a door example which describes in detail the THERM modeling steps THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 73 8 SPECIAL CASES 8 7 Spacers 8 7 Spacers 8 7 1 Overview THERM has the capability to model spacers in great detail so that modeling of spacer effective conductivity is no longer needed Spacer models can be easily reshaped in THERM and the program s cut and paste feature allows spacers to be copied into
189. dDividedLite THM Figure 8 26 Draw the polygons to represent the divider THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 Draw the divider in the cavity between the two glazing systems 8 25 8 SPECIAL CASES 8 3 Dividers 5 Fill the cavities between the divider and the glass layers and inside the divider with the material Frame Cavity NFRC 100 Divide the cavities up according to the 5 mm rule as necessary Check the emissivity values for the inside surface by double clicking on the surface of the extruded metal divider set to the appropriate value from NFRC 101 based on the applicable material type and finish Frame Cavity Surface X XN oa k NE mizzivi 0 200 P YE missivity i i K Cancel l l mi l l Fill the divider frame cavities with the material Frame Cavity NFRC 100 Note that the 5 mm rule for linking glazing and frame cavities does not apply to dividers Frame cavity material is modeled as either air filled or gas filled as appropriate Figure 8 27 Fill the divider frame cavities with Frame Cavity NFRC 100 THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 26 8 SPECIAL CASES 8 3 Dividers 6 Add the polygons for the simulated divided light elements on either side of the glazing system and assign the appropriate materials to them THERM 6 3 SimulatedDividedLite THM 10 x File Edit View Draw Libr
190. de 2 a ih eee are Temperstue 7S35 C splayed Emissivity 0 90 This vinyl frame is modeled with these areas set to Frame Cavity NFRC 100 because the frame If the Nusselt number Nu was tested with these areas taped If the frame is is lt 1 20 it is not necessary not tested this way these areas would not be to apply the 5 mm 0 20 filled with a frame cavity rule Figure 6 8 THERM uses the ISO 15099 rectangularization specification to model the thermal characteristics of cavities The best method for determining whether a frame cavity with a 5 mm 0 20 throat will have to be divided up and how to divide it if necessary is the following 1 Verify that there are throats constrictions in the frame cavity less than or equal to 5 mm 0 20 inches If there are no throats do not break up the frame cavity If throats are present check the Nusselt Number of the undivided frame cavity If the Nusselt Number is less than or equal to 1 20 the simulator shall not break the frame cavity into smaller polygons 2 If the Nusselt number of the undivided frame cavity is greater than 1 20 the simulator shall THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 6 11 6 3 Draw the Cross Sections 6 MODELING FRAME AND EDGE HEAT TRANSFER WITH THERM a Working from the largest part of the frame cavity to the smallest i Identify all horizontal throats constrictions in the frame cavity that are less than or equal to 5 mm
191. defined between them 6 6 Calculating Results When the boundary conditions have been correctly defined for the cross section the model can be simulated Begin the calculation by either clicking on the Lightning Bolt toolbar button selecting the Calculation Calculation menu option or pressing F9 6 6 1 Meshing The first step performed by THERM in the simulation is to generate a mesh from the geometry on which the thermal analysis is based This mesh is generated automatically and a summary of how it works is found in Appendix C in the THERM User s Manual The one variable in the mesh generation that the user can control is the Quadtree Mesh Parameter which determines how fine the mesh is The larger the mesh parameter value the smaller the largest element in the mesh is The NFRC required default value for the mesh parameter is 6 as shown in Table 6 4 Occasionally the mesh generator cannot create a closed mesh with the geometry that has been drawn usually created because of extremely fine detail in the cross section THERM circles the point s where the mesher failed If this happens first Rerun the problem with a higher mesh parameter value This causes the program to generate a finer mesh and results in longer run times The default mesh parameter value is 6 Mesh parameter values ereater than 8 are rarely needed for single cross sections but may be needed for full height product simulations Options Preferences Simulation ha
192. del AutoEnclosure U factor Tag Frame BC NFRC 100 2001 Exterior U factor Tag None BC NFRC 100 2001 Exterior U factor Tag SHGC Exterior fo BC Adiabatic U factor Tag None Figure 8 159 Define the boundary conditions for each Sill Non Retractable Open Venetian Blind cross section THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 174 BC NFRC 100 2001 Exterior U factor Tag None 8 SPECIAL CASES 8 14 Venetian Blinds Between Glass Integral BC Adiabatic U factor Tag None I E BC lt glazing system name gt U factor Inside Film Radiation Model AutoEnclosure U factor Tag None BC lt glazing system name gt U factor Inside Film Radiation Model AutoEnclosure U factor Tag Edge BC Interior lt frame type gt Convection only Radiation Model AutoEnclosure U factor Tag Frame BC NFRC 100 2001 Exterior U factor Tag SHGC Exterior foo BC Adiabatic U factor Tag None Figure 8 160 Define the boundary conditions for each Jamb Non Retractable Open Venetian Blind cross section 5 Simulate each cross section and save the results THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 175 8 SPECIAL CASES 8 14 Venetian Blinds Between Glass Integral In WINDOW 1 Frame Library Import the THERM files into the Frame Library Frame Library C Users Public ALBE NLY N DO 6 wey enetian mdb Frame E dge Edge Glazing Uvalue Uvalue Correl
193. diate Pane Example Head Link spacer cavity to glazing system cavity above if appropriate Because this is a sealed unit the 5 mm rule for linking frame cavities and glazing cavities does not apply Therefore the cavities around and inside the spacer that are next to the glazing cavity are linked to that cavity See Section 6 4 4 Figure 8 130 Example head with framed intermediate pane Example Caming Divider Caming if it exists is modeled as a Divider See Section 8 3 Dividers for modeling rules THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 143 8 SPECIAL CASES 8 14 Venetian Blinds Between Glass Integral 8 14 Venetian Blinds Between Glass Integral NERC has approved using WINDOW and THERM to model venetian blinds between glass for vertical products only no tilted products Venetian blinds between glass venetian blinds between two glazing layers in a glazing system fall into the category of a dynamic glazing product The rules for rating dynamic glazing products according to NFRC 100 and 200 state that they must be rated in both their fully open and fully closed positions In the case of modeling retractable integral venetian blinds as part of a dynamic glazing product the fully open position is when the venetian blind is completely retracted However even when completely retracted the stacked venetian blind slats become a block of material that must be modeled outside inside
194. diating nodes divided by the associated temperature difference gives an effective radiation heat transfer coefficient The measure of the heat transmission through the fenestration product is its overall U factor which is the inverse of the total thermal resistance in the absence of solar radiation The measure of energy transfer due to solar radiation is the Solar Heat Gain Coefficient or SHGC which is calculated from the solar optical properties of the glazing and framing system and the portion of absorbed solar energy that is transmitted to the indoor side To accurately model glazing systems with multiple spectrally selective glazings i e glazings with solar optical properties which vary by wavelength such as many low emissivity coatings a multi band model is 42000 Sune 2013 THERM6 3 WINDOWG6 3 NFRC Simulation Manual 4 SUMMARY OF ALGORITHMS 4 2 WINDOW Computational Method used in WINDOW In this model WINDOW calculates the transmittance and reflectance for the glazing layer or the glazing system wavelength by wavelength and then weights the properties by the appropriate weighting functions to obtain the total solar visible thermal infrared properties as well as the damage weighted transmittance and the transmittance between 0 30 and 0 38 microns To use the multi band model WINDOW needs a spectral data file for each glazing layer These data files are updated and maintained by LBNL and available from NFRC If some of the glazin
195. ding to ISO 15099 Section 6 7 1 which states that cavities greater than 2mm but equal to or less than 10 mm shall be modeled as slightly ventilated air cavities The THERM Material Library has a default material for this case called Frame Cavity Slightly Ventilated NFRC 100 which will be used to fill the entire cavity The figure below illustrates this A cavity open to the exterior environment should be modeled creating a polygon only when d b If 2 mm lt b lt 10 mm the cavity should be modeled as Frame Cavity Slightly Ventilated NFRC 100 For cavities lt 2 mm use Frame Cavity NFRC 100 For cavities gt 10 mm do not model a frame cavity In this example where the opening to the outside narrows to 10 mm is where the slightly ventilated cavity would start a polygon is created and defined with the material Frame Cavity Slightly Ventilated NFRC 100 Figure 6 11 Slightly Ventilated exterior cavities If there are openings lt 2 mm that open into a frame cavity defined as Frame Cavity Slightly Ventilated NFRC 100 these small cavities shall be defined as the standard Frame Cavity NFRC 100 Frame Cavity Slightly Ventilated NFRC 100 lt 2mm Define this frame cavity as the standard Frame Cavity NFRC 100 Figure 6 12 Small cavities adjoining slightly ventilated cavities THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 6 13 6 3 Draw the Cr
196. dit View Draw Libraries Options Calculation Window Help 15 x 18 x DSHS SB boetiaylrbLaqgesed Fi eul Step 3 Click on the Calculation Show U factors Step 1 Click on the menu choice to see the U factor results Calc toolbar button to start the simulation Step 2 When the simulation is finished the results specified in Ulas lee J Latah x i Wi frm B E mm Rotation the Calc Display Options menu Frame 2 5306 22 2251 50 0 Projected in Glass Plane gt choice will be drawn on the model In this example isotherms are displayed The Show Results toolbar button will toggle the results display on and off SHGC Exterior wv 2 4943 Z Error Energy Horm 5 69 ky 43 7 185 5 ldx dy 40 6 208 4 len 212 3 Step 10 0 mm Ready Vertical Divider U factor results NUM 4 Figure 8 30 Calculate the results 9 Save the file using the File Save As menu choice THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 29 0 Edge 2 7734 329 0 f ZF 30 0 Projected in Glass Plane 329 0 22 2251 30 0 Projected in Glass Plane Export F A Li 8 29 8 SPECIAL CASES 8 3 Dividers 10 Import the results to the WINDOW Divider Library as shown below See Section 4 7 3 Importing THERM files in the WINDOW User s Manual for more information about importing THERM files sa Divider Library C Program Files LENL WINDOW63 Dividers mdb ioj x File Edit Libraries Record Tools wiew He
197. dows include casements awnings and hoppers hinged at the side top and bottom respectively Some manufacturers also make pivoting and combination windows that allow for easier cleaning of the exterior surfaces Hinged windows especially casements project outward providing significantly better ventilation than sliders of equal size Because the sash protrudes from the plane of the wall it can be controlled to catch passing breezes but screens must be placed on the interior side Virtually the entire casement window area can be opened while sliders are limited to less than half of the window area 2 2 2 Sliding Windows Sliders are the most common type of windows and include horizontal sliders and single hung and double hung windows Ventilation area can vary from a small crack to an opening of one half the total glass area Screens can be placed on the exterior or interior of the window unit In double hung or double sliding units both sashes can slide In double sliding units the same net amount of glass area can be opened for ventilation as in single sliders but it can be split between the top and bottom or two ends of the window for better control of the air flow 2 2 3 Sliding Glass Doors Sliding glass doors patio doors are essentially big sliding windows As extremely large expanses of glass patio doors exaggerate all of the issues related to comfort and energy performance Since the proportion of glass to frame is very hig
198. e View All tab If you try to load an invalid layer into a laminate from the View All view of the database an error message will be displayed THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 119 8 SPECIAL CASES 8 11 Creating a Laminate in Optics for NFRC 8 11 3 4 Add Glazings to a Laminate You can add monolithic coated and interlayer type layers to a laminate as long as you follow the laminate building rules see 8 11 3 3 Add Layers to a Laminate above To add layers from the current database to a laminate Select the first available unoccupied layer in the laminate by clicking on its layer button if you select an occupied layer it will be replaced see 8 11 3 8 Replace a Layer in a Laminate Click on the Layer Glazing System Laminate at p button in this case ayer om Ho TE 1 of an unoccupied Filename layer zolar T solar Af solar Ab photopic T photopic Af photopic Ab Figure 8 109 Click on the 1 layer button to add the first glass layer Select the Add glazing tab in the database Product ame Naminal m Nominal in Thickness Manufacturer HFRC_ID Acceptance Monolithic CLEAR 3DAT Generic Clear Gl 3mm double 14 8 3 048 Generic 102 Meroe BRONZE BAT Generic Bronze femm i S740 oenerie fim Meroe CLEAR enat Genero carci femm fia svisloeneie fios Figure 8 110 Select
199. e Modeling THERM 9 37 94 9 Total Product U Factor secie a die anand 9 41 9 4 6 Individual Product SHGC and VT usine SHGC O0 amp Vand VTO amp Vississiisarsisseisectsvavartcassansteaviiovssenanes 9 42 DAT Sky WOME ra wil OS sinma a etaseteatgesaetiaas 9 45 OD PHO OIGIM A DO OT ssn a e 9 46 DD Na Deser p MOM zeascesccactectsctaiers tes A Na omcoaeacadtccnmatiass 9 46 232 KEV ZA ON ANI siecle sith A R E A a 9 46 9 5 3 Center of Glazing Modeling WINDOW sesser 9 47 9 5 4 Edge of glazing and Frame Modeling for U Factor THERM 9 48 9 5 5 Total Product U Factor SHGC and VT oun eceeeeeccceeeecceeeees 9 61 9 5 6 Wood Stile and Rail Door Drawings eee eeeeseeeeseeeseeeseeeeneeees 9 61 10 ACKNOWLEDGEMENTS 0 ceeeeeceeeeeee cece ee eeeeeeeeeseeeeeeseeeeeeseanes 10 1 APPENDIX A The Application of ISO 15099 to NFRC 10030A 2 iia cee ataececeh a tans tcustawetensnanceannteneeie A 1 APPENDIX B Referent S poccomunimunisniona a B 1 THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 1 INTRODUCTION 1 1 Overview This document the THERM 6 3 WINDOW 6 3 NFRC Simulation Manual discusses how to use the THERM and WINDOW programs to model products for NFRC certified simulations and assumes that the user is already familiar with those programs In order to learn how to use these programs it is necessary to become familiar with the material in both the THERM User s Manual and the WINDOW User s Manual This manual cove
200. e Producth ame Manufacturer Type Material Openness 3000 Shira White YB Closed Slim White Venetian Blind Pella Wenetian White Venetian Blin 0 000 3001 slim White YB 45 Slim White Venetian Blind Pella Venetian White Venetian Blin 0 500 3002 Slim White Open Slim White Venetian Blind Pella Venetian White Venetian Blin 1 000 3003 Slim Marne Closed Slim Marine Blue Venetian Blin Pella Wenetian Marine Venetian Blir 0 000 3004 SlimMarne 45 Slim Marne Blue Yenetian Blin Pella VWenetian Marne Venetian Blir 500 3005 Slim Marine Open Slim Marne Blue Yenetian Blin Pella Venetian Marne Venetian Blir 7 900 5000060 Wiraspan TM Medium Gray 946 30 Viraspan T MM Ceramic Frit Mec Viracon Fritted glass 5001 Simulated Sandblast 1086 70 Translucent Frit Simulated Sar Viracor Fritted glass Figure 8 148 Import the appropriate records from the CGDB Shading Layer Library THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 164 8 SPECIAL CASES 8 14 Venetian Blinds Between Glass Integral If only one slat geometry is represented in the CGDB import that record into the working database and then make new records for the missing slat geometries so that there is a separate Shading Layer record for both the Open and Closed geometries Shading Layer Library ID 3002 Mame Slim White Open Product Hame Slim white Venetian Blind Manufacturer Pela O The Material references a Type Venetian blind horizontal record in th
201. e Shade Material Library which is Material 31111 White Venetian Blind Slat whit automatically created when the Shading Layer is imported from the CGDB Effective Openness Fraction 1 000 Venetian Blind Slat width i48 mm o is Spacing 120 mm Ho Tilt angle o o TE Blind thickness 148 mm Rise Figure 8 149 Define the venetian blind geometry for the open horizontal slats e Type Venetian blind horizontal e Material White Venetian Blind Slat this pulldown references the record in the Material Library that is associated with this Shading Layer When a Shading Layer is imported from the CGDB the associated record for the material is automatically added to the Shade Material Library If you need to make a new Shading Layer record for a different slat geometry make sure to reference the same material record in the Shade Material Library e Effective Openness Fraction If a Shading Layer is imported from the CGDB this value will automatically be set If you are making a new record the Effective Openness Fraction 1 for the Open blind case e Slat Width appropriate value in this example 14 8 mm e Spacing spacing between each slat in this example 12 mm THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 165 8 SPECIAL CASES 8 14 Venetian Blinds Between Glass Integral e Tilt fully open 0 for a slat in the horizontal position gars i a a slat thickness S Zar
202. e Source is User this ID is assigned automatically by WINDOW but can be overwritten by the user as long as it is unique Name The name of the glass layer If the record was imported from the International Glazing Database this name will automatically come from that database Product Name The Product Name field from the International Glazing Database 5 2 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 5 MODELING CENTER OF GLAZING WITH WINDOW 5 2 Glass Library Manufacturer Source Mode Color Thickness Tsol Rsol1 Rsol2 Tvis Rvis1 Rvis2 Tir emis1 emis2 The name of the glass manufacturer If the record was imported from the International Glazing Database this name will automatically come from that database Source of the glass record Current options are IGDB v lt nn n gt Indicates that the data was imported from the International Glazing Database IGDB with the database version number such as 11 4 These records will have the spectral data information from the International Glazing Database User Indicates that the data was created when the user copied an existing record into a new record User defined records will not have associated spectral data values An identifier to determine if the glass layer is approved by NERC Only records with in this field can be used for NFRC simulations except for laminates and applied films that are imported from the Optics6 User Database See Se
203. e VB Closed 15 oO 0 000 0 900 0 900 160 000 eli Gap2 1 Air 10 2 O u W Glass 7 ee 9921 LOW E_3 LOF 30 o6s2 0122 0112 0824 0115 0110 0000 0156 0 840 1 000 4 Cenyt of Glass Results Temperature Data Optical Data Angular Data Color Properties l Ufactor Rel Ht Gain Gap 1 Ket Gap 2 Ket Wat re Wt rE Wat rE 7 Find ID v 19 records found Name ProductName Manufacturer Venetian B45 ISO 15099 appendix Venetian i Venetian B90 ISO 15099 appendix Venetian Click on the Venetian CO ISO 15099 appendix Venetian double arrow Venetian C45 ISO 15099 appendix Venetian to see the Venetian C80 ISO 15099 appendix Venetian Shading Venetian C90 ISO 15099 appendix Venetian Layer Library Venetian DO ISO 15099 appendix Venetian list Venetian D45 ISO 15099 appendix Venetian Venetian D90 ISO 15099 appendix Venetian White Frit Generic Fritted glass Clear Frit no pigme Generic Fritted glass en Slim White VB Close Slim White Venetian Blind Pella 3002 SlimWhiteOpen Slim White Venetian Blind Pella Venetian 5000 Viraspan TM Medi Viraspan TM Ceramic Frit Mec Viracon Fritted glass 5001 Simulated Sandblast Translucent Frit Simulated Sar Viracon Fritted glass Figure 8 168 For the middle layer in the Glazing System Layer 2 select the venetian blind from the Shading System Library e Set Number of layers 3 e Set Layer 2 to Shade from pulldown arrow to the left in the first column e Set Dtop Dbot
204. e air Interior Boundary idth 15 Layers 2 aa ie Condition Use Ucenter 1 78 9 wm2 K re Spacer convection plus Thickness 25 396 mm Draw spacer nclosure radiation Single spacer for multiple glazings Material Fiberglass PE Resin x Shading layers None Close WINDOW Glazing System Library EAM y Dropbor Projects N FACS imi Browse Window 6 Databaze Default Bounda Conditions Use U factor values C Use SHGC values Extenor Boundary Condition Interior Boundary Condition Use existing BC from library select below Use convection plus enclosure radiation ki NFAC 100 2010 Exterior x y 2 886 2 929 dx dy6 957 6 913 len 9 808 Step 0 394 inches Provides access to WINDOW Glazing System Libraries Figure 8 12 Import the first glazing system THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 11 8 SPECIAL CASES 8 3 Dividers 3 Import the glazing system again as an additional glazing system below the first one the locator does not have to be moved but facing down this time Use the following settings for this glazing system Orientation Down CR Cavity height 1000 mm 39 inches Sight line to bottom of glass 0 Spacer height 0 Edge of Glass Dimension 63 5 mm 2 5 inches Glazing System Height 150 mm 6 0 inches Sight line to shade edge 0 not modeling shading system Draw spacer Not checked Insert the glazing system as an Additional Glazin
205. e and Edge dimensions ee Frame Height Edge Height The figures on the following pages show the THERM cross sections and U factor results for this window THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 9 51 9 5 Problem 4 Door 9 SAMPLE PROBLEMS Sill Modeling Assumptions Cross Section Sill Gravity Vectane4 Gravity Arrow Down BC Adiabatic U Factor Surface tag None BC Interior Wood Vinyl Frame convection only Radiation Model AutoEnclosure U Factor Surface tag Frame U Factors eee xl U factor delta T Length Wi ma F A otation mm Frame 2 3649 39 0 fi 03 187 na Projected 7 2 SHGE Exterior 2 3649 33 0 fi 03 187 na Projected Y z BC NFRC 100 2010 Exterior Radiation Model Blackbody U Factor Surface tag SHGC Exterior 63 5 mm BC Adiabatic U Factor Surface tag None 34 Error Energy Norm PBB Export Figure 9 45 THERM cross section and U factor results for the sill cross section 9 52 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 9 SAMPLE PROBLEMS 9 5 Problem 4 Door Jamb Gravity eckorse 4 Modeling Assumptions Cross Section Jamb Gravity Arrow Into the screen BC Adiabatic U Factor Surface tag None BC NFRC 100 2010 Exterior Radiation Model Blackbody U Factor Surface tag SHGC Exterior BC Interior Wood Vinyl Frame convection only Radiation Model AutoEnclosure U Factor Surfac
206. e and have good insulating value by incorporating air cavities similar to vinyl 2 4 5 Wood Composites Most people are familiar with composite wood products such as particle board and laminated strand lumber in which wood particles and resins are compressed to form a strong composite material The wood fenestration product industry has now taken this a step further by creating a new generation of wood polymer composites that are extruded into a series of lineal shapes for frame and sash members These composites are stable and have the same or better structural and thermal properties as conventional wood with better moisture resistance and more decay resistance They can be textured and stained or painted much like wood They were initially used in critical elements such as sills and thresholds in sliding patio doors but are now being used for entire units This approach has the added environmental advantage of reusing a volume of sawdust and wood scrap that would otherwise be discarded 2 4 6 Hybrid and Composite Frames Manufacturers are increasingly turning to hybrid frame designs that use two or more of the frame materials described above to produce a complete fenestration product system The wood industry has long built vinyl and aluminum clad products to reduce exterior maintenance needs Vinyl manufacturers and others offer interior wood veneers to produce the finish and appearance that many homeowners desire Split sash designs may
207. e coating is on the inside of the glass layer Glazing System Library ID 3 Mame Double Low e Air Layers E A Tilt 90 Il Height 1000 00 rmm Environmental TA Conditions NFRC 100 2010 IG width 1000 04 mm Comment Overall thickness a FOO mm Mode E ID Name Mode Thick FReoll Asol2 Tvis Avisl Avise i E2 Cond Glass 17 H 925 CMFTIR_3 AFG 3 0 0456 0 331 0 395 0 780 0158 0 126 0 000 0 840 0 033 1 000 Gapi 1 Al 127 L Glass 2 H 103 CLEAR_E DAT 6 0 C 0 771 0 070 0070 0 884 0 080 0 080 0 000 0 840 0 840 1 000 Figure 5 9 Use the Flip checkbox to flip the coatings on a glass layer THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 5 9 5 3 Glazing System Library Center of Glazing U factor 5 MODELING CENTER OF GLAZING WITH WINDOW 5 3 3 Gas Fill The gas used to fill the gap between the glass layers makes a significant contribution to the center of glazing U factor although it does not have much affect on the Solar Heat Gain Coefficient For NFRC certified simulations the gas to be shipped in the fenestration product shall be modeled When creating a glazing system in WINDOW choose the appropriate gas fill from the Gas Library which contains the maximum gas fills that can be used as shown in the figure below Custom gas mixtures can be defined in the Gas Library See the WINDOW User s Manual for more details about making a new gas mixture in the Gas Library When a gas is used to fill the
208. e expensive Because of the difficulties discussed above it is apparent there are physical and economic limits to the number of layers of glass that can be added to a fenestration product assembly However multiple pane units are not limited to assemblies of glass One popular innovation is based on substituting an inner plastic film for the middle layer of glass The plastic film is very lightweight and because it is very thin it does not increase the thickness of the unit The glass layers protect the inner layer of plastic from scratching mechanical abuse corrosion weathering and visual distortions caused by wind pressure Thus the strength and durability of plastic as a glazing material are no longer issues when the plastic is protected from physical abuse and weathering by inner and outer layers of glass The plastic films are specially treated to resist UV degradation and they are heat shrunk so they remain flat under all conditions The plastic inner layer serves a number of important functions It decreases the U factor of the fenestration product assembly by dividing the inner air space into multiple chambers Units are offered with one or two inner layers of plastic Secondly a Low E coating can be placed on the plastic film itself to further lower the U factor of the assembly Also the plastic film can be provided with spectrally selective coatings to reduce solar gain in hot climates without significant loss of visible transmittance T
209. e fritted glazing system 5 Import the THERM files into the WINDOW Frame Library 6 Make the appropriate Window records using the fritted glazing system and the THERM files with the fritted glazing system In WINDOW 1 Shading Layer Library If the appropriate fritted product is not already in the Shading Layer Library import it from the Complex Glazing Database CGDB If the product is not in the CGDB the manufacturer will need to have the fritted product measured and added to the CGDB before the product can be simulated 2 Shade Material Library When the fritted layer is imported from the CGDB Shading Layer Library into WINDOW the associated records will automatically be imported into the Glass Library In general you should not have to manipulate these records in the Glass Library 3 Glazing System Library Define the glazing system with the venetian blind between two layers of glass In THERM 7 Frame Geometry Draw the frame geometry including Head Sill Jamb and Meeting Rail if appropriate 8 Glazing System Import the glazing system defined with the fritted glass into the frame geometry 9 Boundary Conditions For fitted glass products set Shading System Modifier to None the default 10 Simulate the model save the results In WINDOW 11 Frame Library Import the THERM files into the Frame Library 12 Window Library Construct the window using the THERM files in the Frame Library and the glazing sy
210. e normally not adequate to contain special low conductance gases In a double seal system a primary sealant typically butyl seals the spacer to the glass to prevent moisture migration and gas loss and a secondary backing sealant often silicone provides structural strength When sputtered Low E coatings are used with double seal systems the coating must be removed from the edge first edge deletion to provide a better edge seal Since aluminum is an excellent conductor of heat the aluminum spacer used in most standard edge systems represented a significant thermal short circuit at the edge of the IGU which reduces the benefits of improved glazings As the industry has switched from standard double glazed IGUs to units with Low E coatings and gas fills the effect of this edge loss becomes even more pronounced Under winter conditions the typical aluminum spacer would increase the U factor of a Low E gas fill unit slightly more than it would increase the U factor of a standard double glazed IGU The smaller the glass area the larger the effect of the edge on the overall product properties In addition to the increased heat loss the colder edge is more prone to condensation Fenestration product manufacturers have developed a series of innovative edge systems to address these problems including solutions that depend on material substitutions as well as radically new designs One approach to reducing heat loss has been to replace
211. e rating simulation it is necessary to determine the mid point of the frame which is most easily done before the glazing systems are inserted Draw a rectangle from the sightline highest interior point for both glazing systems going horizontally in both directions so that each rectangle is larger than the horizontal dimension of the frame On both the right and left side of the frame draw a rectangle between the other two reference rectangles and make sure it contacts the frame Measure the exterior rectangle just created in the vertical dimension The midpoint of the frame is half of this dimension For both the right and left sides of the frame cross section select the vertical frame component and insert a point on the frame at the midpoint dimension Step 1 Draw two reference rectangles top and bottom from the sightline larger than the depth of the frame cross section Sightline Step 4 Select the vertical frame Step 3 components and insert a point at the Measure the midpoint as measured in Step 3 vertical rectangles and This will define the midpoint of the frame determine the for the half height frame dimension for midpoint half the the rating simulation vertical dimension of each rectangle 4 Step 2 Draw two reference rectangles right and left between the top and bottom rectangles Figure 8 92 Determine the frame mid points mull_midpoint thm Finish the cross sect
212. e tag Frame 63 5 mm T BC Adiabatic U Factor Surface tag None Ix U factor delta T Length Ww fim E L mm Rotation SHGC Exterior f 47 39 0 55 725 NA Projected 7 Frame 1 9347 E 85 725 na Projected Ka 2 Export Z Error Energy Norm 445 por lt Figure 9 46 THERM cross section and U factor results for the jamb cross section THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 9 53 9 5 Problem 4 Door 9 SAMPLE PROBLEMS Head Modeling Assumptions Gravity ectone s Cross Section Head Gravity Arrow Down BC Adiabatic U Factor Surface tag None BC Interior Wood Vinyl Frame convection only Radiation Model AutoEnclosure U Factor Surface tag Frame BC NFRC 100 2001 Exterior Radiation Model Blackbody U Factor Surface tag SHGC Exterior BC Adiabatic U Factor Surface tag None U Factors x U factor delta T Length Wi mg E L mm Rotation Frame fi Ge 39 0 85 25 Na Projected si SHGC Exterior fi 3355 39 0 85 725 Nea Projected r bd Z Error Energy Norm 4 52 Export Figure 9 47 THERM cross section and U factor results for the head cross section 9 54 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 9 SAMPLE PROBLEMS 9 5 Problem 4 Door Door Core Modeling Assumptions Gravity Yectone 4 Cross Section Head Gravity Arrow Down BC Adiabatic U Factor Surface tag None BC NFRC 100 2010 Exterior Radiation Mod
213. ecause the throat where it connects to the glazing cavity is greater than 5 mm Glazing cavity Glazing cavity These polygons are not linked to the glazing cavity because the throats where they connect to the glazing cavities below are less than 5mm They are defined as Frame Cavity NFRC 100 See Section 6 4 4 for more information about linking cavities Figure 8 156 Fill the remaining cavities and link to the appropriate glazing system cavities THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 171 8 SPECIAL CASES 8 14 Venetian Blinds Between Glass Integral 3 Create the other cross sections in this manner In the case of the Head and Sill cross sections the Sight Line to Shade Edge is zero However for the Jamb cross section the blind does not touch the edge of the frame but rather is 3 mm off the frame so the Sight Line to Shade Edge is non zero Head Cross Section Sill Cross Section Jamb Cross Section Figure 8 157 Head Sill and Jamb cross sections for Non retractable Open Venetian Blind between glass layers Integral 4 Boundary Conditions The program will not automatically insert a point in the exterior glass layer for the SHGC Exterior U factor tag so you will need to do that by hand by editing the glazing system For Integral Venetian Blinds the Shading System Modifier choice will automatically be set to None THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 172 8
214. ecords WINDOW will add each THERM file to the Frame Library as a separate record assigning the THERM file name as the record name by default If necessary set in WINDOW File Preferences Calculation Options the Default Frame Absorptance to 0 30 or 0 50 according to the NFRC 200 specifications THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 6 45 6 6 Calculating Results 6 MODELING FRAME AND EDGE HEAT TRANSFER WITH THERM se W6 Frame Library C Program Files LBNL WINDOW63 w6 mdb l Ioj x Fie Edit Libraries Record Tools wiew Help WER AE gt n Bae hi oF Frame Library C 4Prograrn Filess LENLSWwINDOWE S446 mdb Detailed View Edge Edge Glazing Uvalue Uvalue Correlation Thickness Wi moe K Wi Aroe K mm Al w break ASHRAE WA 5 630 NAA Class Naa 0 30 Update Name Source Type Copy Al flush ASHRAE NA 3 970 HA Class N A i 0 90 Delete Wood ASHAAE NA 2270 NA Class 0 90 Winyl ASHRAE N A 1 700 NA Clase 0 90 sample aill THM Therm Sill 2 001 2 344 0 30 sample jamb THM Therm Jamb Advanced T records found Import Export Import eee Report Therm file Format Print Window 5 or 6 Database Therm file Iv For Help press F1 Step 1 In the WINDOW Frame Library List View click on the Import button Open Ha Look in Samples de E ET Ez Divider THM a sample head THM a sample jamb THM a sample sill THM sam
215. ective conductivity of thermal bridging elements e g bolts screws etc Keff Fb Kb Fn Kn Equation 1 where Fb Fraction of the Length which contains the thermal bridging elements see equation 4 below Fn the fraction of the Length which contains non thermal bridging elements see equation 5 below Kb conductivity of the thermal bridging elements Kn conductivity of the non thermal bridging elements from the sum of the resistances Rt of individual elements from Equation 2 below Assume a default value of 0 024 W m K for air cavities This methodology should be applied with the following caveats If less than 1 to obtain percentage multiply fraction by a 100 of the Length is made of thermal bridging elements such as stainless steel i e Fb lt 0 01 do not model the thermal bridging elements If between 1 and 5 of the Length is made of thermal bridging elements 0 01 lt Fb lt 0 05 and if the conductivity of the thermal bridging elements is more than 10 times the conductivity of the thermal break model the thermal bridging elements using the keff calculated in Equation 1 If more than 5 of the length is made of thermal bridging elements Fb gt 0 05 model the thermal bridging elements using the keff calculated in Equation 1 Calculate the total resistance of the non thermal bridging elements Rt by summing individual resistances non thermal bridging element conductivity for each non thermal bridgin
216. ed in the project database Glazing System Library All the glazing systems referenced in the Window Library entries Frame Library All the frames referenced in the Window Library entries Divider Library All the dividers referenced in the Window Library entries if dividers are modeled Glass Library All the glass layers referenced from the glazing systems used in the Window Library entries Gas Library All the gases referenced from the glazing systems used in the Window Library entries Environmental Conditions Library All the environmental conditions referenced from the glazing systems and the Window Library entries Shading Layer Library Any records in the Shading Layer Library that are referenced from the glazing systems that are exported to the Project Database Shade Material Library Any shade material records that are referenced from the Shading Layer Library if Shading Layers are modeled in the exported glazing system Start from the Glazing System Library this will mean that records from the libraries used to define the glazing systems will be written into the project database and no other entries Glazing System Library All the glazing systems referenced in the Window Library entries Glass Library All the glass layers referenced from the glazing systems used in the Window Library entries Gas Library All the gases referenced from the glazing systems used in the Window Library entries Environmental Conditions Libr
217. ed radiation is 0 1 i reflected back into the interior suitable for a O mila to cold climate 29 1 0 5 0 10 0 50 0 UV Visible Solar infrared Long wave infrared Wavelength micrometers Figure 2 3 Ideal spectral transmittance for glazings in different climates Source Sensitivity of Fenestration Solar Gain to Source Spectrum and Angle of Incidence ASHRAE Transactions 10 R McCluney June 1996 2 6 9 1 Coating Placement The placement of a Low E coating within the air gap of a double glazed fenestration product does not significantly affect the U factor but it does influence the solar heat gain coefficient SHGC That is why in heating dominated climates placing a Low E coating on the 3 surface outside surface of the inner pane is recommended to maximize winter passive solar gain at the expense of a slight reduction in the ability to control summer heat gain In cooling climates a coating on the 2 surface inside surface of the outer pane is generally best to reduce solar heat gain and maximize energy efficiency Manufacturers sometimes place the coatings on other surfaces e g 2 surface in a heating climate for other reasons such as minimizing the potential for thermal stress Multiple Low E coatings are also placed on surfaces within a triple glazed fenestration product assembly or on the inner plastic glazing layers of multipane assemblies referred to as superwindows discussed later in this chapter with a cumulative
218. el Blackbody U Factor Surface tag SHGC Exterior BC Interior Wood Vinyl Frame convection only Radiation Model AutoEnclosure U Factor Surface tag Door Core BC Adiabatic U Factor Surface tag None x U factor delta T Length Wim E E Rotation mm SHGC Exterior 2 051 2 39 0 E35 M A Projected r h Door Core 2 051 2 39 0 63 5 Nia Projected 7 E t Error Energy Norm 0 00 por Figure 9 48 THERM cross section and U factor results for the door core cross section THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 9 55 9 5 Problem 4 Door 9 SAMPLE PROBLEMS Panel Edge BC Adiabatic xj U Factor Surface tag None Modeling Assumptions Cross Section Sill Gravity Arrow Down BC NFRC 100 2010 Exterior Radiation Model Blackbody U Factor Surface tag SHGC Exterior BC Interior Wood Vinyl Frame convection only Radiation Model AutoEnclosure BC Adiabatic U Factor Surface tag None U Factors x U factor delta T Length Wi fm F C mm Rotation SHGC Exterior 2 7593 39 0 101 974 na Projected Y Frame 2 7592 393 0 fi 01 974 na Projected Y ih E t Error Energy Horm 4 308 spor E Figure 9 49 THERM cross section and U factor results for the panel edge cross section 9 56 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 9 SAMPLE PROBLEMS 9 5 Problem 4 Door Panel Core BC Adiabatic U Factor Surface tag No
219. element using Equation 2 Table 8 1 Cross Material Conductivity Depth R Section W mK m m2K Element W Air cavity default value 0 024 0 00392 0 16333 2 Aluminum 160 0 003175 0 0000198 conductivity from THERM Material Library 3 Vinyl 0 12 0 00586 0 049 conductivity from THERM Material Library Air cavity default value 0 024 0 01411 0 587917 Tot 0 02706 0 800103 Calculate Rt as follows Ri X d k E d1 k1 d2 k2 d3 ks da ka 0 00392 0 024 0 003175 160 0 00586 0 12 0 01411 0 024 0 800103 m2K W D 0 00392 m 0 003175 m 0 00586 m 0 01411 m 0 02706 m Calculate the conductivities as follows Kn DA R 0 02706 0 800103 0 033821 W m K Kb 14 3 W m K stainless steel Calculate the fraction of bolt to no bolt as follows Wb Bolt head width 11 1 mm Sb Bolt spacing 12 304 8 mm Fb Wb Sb 11 1 mm 304 8 mm 0 036 Fb 0 036 100 3 6 Fn 1 Fb 1 0 036 0 964 THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 82 8 SPECIAL CASES 8 8 Non Continuous Thermal Bridge Elements Calculate the new Keff which will be used in THERM as follows Keff Fb Kb Fn Kn Keff 0 036 14 3 0 964 0 033827 0 55 W m K In THERM create a new material in the Material Library with this Keff In the THERM cross section the bolt material should be changed from Stainless Steel to this new material The resulting cross section i
220. en importing the glazing system and simulate it to make sure that the geometry is correct This will be the base case file and will contain no results once the multiple glazing options have been defined and simulated Define the glazing options There are two ways to define the glazing options in a file From the Calculation menu select the Glazing Options menu choice OR Double click on the glazing system geometry and click on the Glazing Options button in the Glazing System Info dialog box June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 6 MODELING FRAME AND EDGE HEAT TRANSFER WITH THERM 6 4 Importing Glazing Systems tHeRm6 3 Deample s THM O ix a File Edit View Draw Libraries Options Calculation Window Help lej x JO a S Bb Oo e fja Caution PE U samplecizsys x Show Results Display Options Shift Fa Show U Factors Ctrl F9 Step 1 Calc Manager w Background Calc Either Add to queue Stop Current Galculation Click on the Glazing System and then click on the Calculation Glazing Options Glazing Options ix menu choice OR l Glazing Sample GlzSys Double click on the Glazing System and ID OK click on the Glazing gene aay na Step 2 wg WimeK Glazing dialog box Te Nominal Thickness 26 510 mm Uptions When the Glazing System Info dialog box opens click on the Glazing Options button Number of Glazings 2 Cancel sill ikp Update Source C Program F
221. ename leave extension blank to use default extension Type a new name for the glazing glass layer Then name should be the NFRC IDs of the glass layer and the applied film 20041563 A dialog box appears asking if you want to review the information fields of the new glass layer Click Yes to change the NFRC ID of the new layer Z One or more of the information Fields Productname Apearehce WFRC ID has been reset by the operation Do you want to reviewlchange these Fields Opticss CTTEITITITI Lrrretrr reer etter eee a Change Glazing Existing Glazing Filename 2004 1 BES usr Product Mame Appearance New Glazing Filename 2004 1563 usr Product Name fo bial et The Change Glazing dialog box NFA ID 20000 NFRC ID oo will be displayed Change the Glazing Type Applied filer Glazing Type Applied filrn NFRC ID to an appropriate and unique for your user database Material NWA ooo number Substrate Filename CLR 6 cIG Film Marne k75 Thickness mm e0 Manutacturer Use Material BAA Substrate Filename LRG Film H ame k75 Thickness mm e0 Hanufacturer lse Coated Side Front of Glazing Exterior Back of Glazing Interior Ok Cancel Figure 8 127 Give the new applied film layer a name and a new NFRC ID number if needed to ensure uniqueness THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 138 8 SPECIAL C
222. entical such as a fixed window with the same cross section for the jambs then only one cross section needs to be modeled for the jamb However the new modeling assumptions for cavities when modeling Condensation Resistance based on ISO 15099 require that different cross sections be modeled for head sill and jambs if those cross sections contain frame cavities If only U factor is being modeled the head and the sill can be combined into one calculation if the geometries for each are the same Although all the Product types listed in Table 4 3 of NFRC 100 are not listed here in Table 6 1 or Figure 6 1 these four basic categories cover all the geometries in NFRC 100 THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 6 1 6 2 Cross Sections to be Modeled Single Lite Fixed Picture Transom Casement Awning etc Two Lite Vertical Vertical Slider Two Lite Horizontal Horizontal Slider Sliding Patio Door Two lite casement Window Wall Curtain Wall Table 6 1 Cross sections to be modeled Operator Number Number of Cross Sections to Model sd Cross Sections to Model Type Minimum Maximum CR amp U Calc U only Calc If Head and Sill are the same If Jambs are the same 5 4 If Left and Right If Head and Sill are the Upper Jambs are the same same and Left and Right Lower Jambs are the same 5 If Head and Sill are the same 4 If Left and Right Head are the same Left and Rig
223. er amb THM Advanced VenetanClosed Head THM 10 records found o mt YenetianClosed Sill THM El For Help press F1 Mode NFRC ist NLM ISCRL ot Figure 8 177 Import the THERM files into the WINDOW Frame Library THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 o x 8 190 8 SPECIAL CASES 8 14 Venetian Blinds Between Glass Integral 2 Window Library Construct the window using the THERM files in the Frame Library and the glazing system defined in Glazing System Library and calculate the results Window Library C Thermdoc THERM 6 2 WINDOW 6 2 NFRC Sim Manual 2009 w6 enetian mdb Ioj xj File Edit Libraries Record Tools View Help Care S Ble Mao neo ei OF z SIRI h Del o Y Name Else Mode NFRO Type Fixed picture gt gt Copy Width 47 244 inches Boge Height 59 055 inches Save Area 19 37 ft2 Report Tilt a0 Environmental Conditions Dividers NFRC 100 2004 Dividers Display mode Horal Total Window Results U factor 0 322 Btu h tt2 F SHEE 0 090 i Mao Detail cR MA Detail Click on a component to display characteristics below Frame Name YenetianClosed l amb THM ue gt 11 Hedge 0 305 Bturh t2 F 2 Edge area O86 Ft Utactor 0 465 Bturh ft2 F PFO 3 449 Area 1 33 fhe Abs 0 300 cl Mode NFRC P MoM SCRL g 4 For Help press F1 Figure 8 178 De
224. erial Library However you may need to reference existing records in the Shade Material Library if you are defining a new Shading Layer record for example to define a differen slat geometry for a product Shade Material Library C 4Users PublicSLENLAWIN DOW Bwb enetan mdb ID Mame Manufacturer Source 97108 White Venetian Blind Slat white tet Pella CODE 31109 White Venetian Blind Slat white tet Fella CODE 97110 White Venetian Blind Slat white tet Pella CODE 31111 White Venetian Blind Slat white tet Pella COCE 31112 Manne Venetian Blind Slat marine txt Pella CODE Figure 8 167 Shade Material Library records are automatically created when Shading Layers are imported from the CGDB THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 180 8 SPECIAL CASES 8 14 Venetian Blinds Between Glass Integral Glazing System Library Define the glazing system with the venetian blind between two layers of glass Glazing System Library ID 25 Hame Lowe blGIz IntyB Closed Layers 3 Tilt g0 IG Height 1000 01 mm ae _e ee Environmental S Eadie NFAC 100 2010 IG Width 1000 00 mm Comment 1 2 Overall thickness 45 056 mm Mode fe ID Name Mode Thick Flip Tol Aso Reol Twiss Aviel Avis2 Tir E E2 Cond hi Glass 1 3501 CLEAR3 LOF 30 J o83r 0075 0075 0899 0083 0083 0o00 0840 0840 1 000 Set Layer 2 Gapi 1 Al 28 4 to Shade a Shade 2 gt 3000 Slim Whit
225. erior or exterior surface of the glass i e snap on grilles Grilles or dividers between glass layers must be modeled under some circumstances as discussed in Section 8 3 Modeling Internal Dividers Optional jamb head and sill extensions Interior or exterior shading devices Nailing flanges which can be removed from a fenestration product and which are removed for testing These may be vinyl flanges on wood windows or flanges on vinyl or aluminum windows designed to be removed for some installations Permanent nailing flanges that would be in place during a test shall be modeled In addition as stated in NFRC 100 including but not limited to screws and bolts in curtainwalls and pour and debridge thermal breaks which are not full debridged shall be simulated For the time being components that do not have to be modeled include Hinges Locks Balances Non continuous Operator Hardware Weep Holes Setting Blocks Shear Blocks Corner Keys 6 3 5 Deformable Parts Because deformable parts such as glazing clips weatherstripping and other snap in parts are often drawn in the undeformed states in DXF files and assembly drawings many times in the DXF files they overlap other parts simulator judgement is still required to ensure that these parts are modeled in a way that results in accurate heat transfer results For example there are several instances when small air gaps can be replaced with solid m
226. es of the complex glazing products and manufacturers submit data to LBNL to be included in the CGDB The current version of the CGDB is located on the LBNL website http windows bl gov software CGDB There is a version of the database for each version of WINDOW at the time of this writing WINDOW 6 and WINDOW 7 The databases are basically just WINDOW databases that only have the complex glazing records in them so the products are easily imported into any WINDOW database keeping in mind the program version compatibility The current WINDOW 6 CGDB database is called W63 CGDB 1 2 mdb And by default will be installed into the following directory depending on your operating system e For Microsoft XP C Program Files LBNL LBNL Shared e For Microsoft Vista and Windows 7 C Users Public LBNL LBNL Shared When you want to import records from the CGDB into the Shading Layer Library of your current WINDOW 6 working database follow these steps 1 Shading Layer Library Import the frit product from the CGDB into the Shading Layer Library In the Shading Layer Library List View click the Import button and browse to the CGCB database Shading Layer Library CO U sers rdmitchell D ocuments My Detailed View Dropbossnfres Tramnings6 TE NFRAC Training for Software Approval Complex Producti ame Yenetian AL Venetian 445 Venetian 490 Yenetian BO Venetian B45 Format Window 5 or 6 Database venetian B30 Import datab
227. ese opposing needs are often met by providing glazing that has high visible transmittance and then adding attachments such as shades or blinds to modulate the transmittance to meet changing needs NFRC reports visible transmittance as a rating on the label Note that NFRC s rating is a whole product rating that combines the effect of both glazing and frame There are many cases where the transmittance of glazing alone will be required so it is important to make sure that the appropriate properties are being compared 3 6 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 3 FENESTRATION HEAT TRANSFER BASICS 3 5 Condensation Resistance In the past products that reduced solar gain with tints and coatings also reduced visible transmittance However new spectrally selective tinted glasses and selective coatings have made it possible to reduce solar heat gain with little reduction in visible transmittance 3 5 Condensation Resistance Condensation has been a persistent and often misunderstood problem associated with windows In cold climates single glazed windows characteristically suffer from water condensation and the formation of frost on the inside surface of the glass in winter The surface temperature of the glass drops below either the dew point or frost point of the inside room air Excessive condensation can contribute to the growth of mold or mildew damage painted surfaces and eventually rot wood trim Since the interior humidity
228. eseeseesessessesressessessresresresressresresreseess 8 2 8 2 2 Steps for Meeting Rail U factor Calculation 8 3 8 2 3 Steps for Meeting Rail Condensation Resistance Calculation 8 8 Fede B highs al ac erent aurea EEO T ee ede Aree Te ee rer near nr ee ere E ere 8 10 8 3 1 Internal Dividers Suspended Grilles eee eeeeeeeeeeeneeeeeeeeees 8 10 One hd Gas Filled Glazing Systems esciti e ES 8 18 O92 SIA ted Divided Cites isson a E 8 22 9 950 True Divided Bites ce fae ay simttostas cartanssne Liesl aat Sure casemeeearsathleast ae 8 31 BAe Door Cann eta ceiastrcusiiaiates slau soh abast taseuceaabebosnatesbiunoautned dace sasuoranintes 8 39 OA LOUIE VV IC OWS etectiat a eta nda Aad atita duvet E 8 45 OTe Modene SLC NS saa alae ronal cds ads 8 45 0 42 Storm Window EXAMP l Enare E N 8 48 8 4 3 Storm Window Meeting Ra ils cinisme i 8 53 8 4 4 Steps for Storm Window Condensation Resistance Calculation eee eeseeseeeseecereeeneeeeees 8 54 6 ORV SINS neca E A EE 8 57 8 0 by Skylioht Modeling Steps visa covevyiisarcansssdsaawdadudasa ious anni 8 57 6 0 2 Skylioht Mountine Details sissicdidvecaitasdsiisseedeinandenliamdoinecea sins 8 59 8 5 3 Example Flush Mounted Skylight Problem seeen 8 59 8 5 4 Domed Skylights Glass Block wo eee ceseeseeeseeeeseeeseeeeeeeeenes 8 69 8 5 5 Sloped Glazing Systems with Large Gaps see eeseeseeeseeeeeeees 8 72 0 OOS sates sais ees ase Gat aot oeaatsevnoateh Wa aiadbacanty E at
229. esrersess 8 117 Od dedi COV CIVIC WY a or AAE E E E E T 8 117 8 11 2 Laminate Interlayer Data eeseseeeeeeeeeeeereereesersresresrersrrsresresresees 8 118 8 11 3 Constructing a Laminate in Optics eeeeseseeesereerrrererererrerersrerss 8 119 8 12 Creating an Applied Film Layer in Optics for NFRC Certification 8 131 O L2 OV CTV E Wesi e a a a ae 8 131 0 22a TU Dala en ree ere ee rte Ter eee eee 8 132 12 3 Using this Procedure for NERC 200r iaeei 8 133 8 12 4 Creating a Layer with an Applied Film in Optics 8 133 6 132 Frained Intermediate Pane tigations ad EEN EN 8 141 BLO Us OVE VIC sci a a a ene aiusansan eae oaral aavaenapatieieeinsonee 8 141 6 10 2 THERM Modeline Details crorcnsnsnisnens nnani 8 142 8 14 Venetian Blinds Between Glass Integral eeeeeeeeerereeeeerersres 8 144 WINDOW aeretercsoniae eo A E AEN 8 147 8 14 1 2 Fully Retracted Open Venetian Blind Between a Double Glazed System and a Third Glazing Layer seeen 8 158 8 14 2 Closed Venetian Blind seeeeeseseeseeeeseresresressersrssresressersresresresses 8 177 OO oh Ora T crt sar erty en cenern rene Wnts 8 192 Ol Dlx IVIOGO Mer SUC DS trance bsassacsana lice tarausagcangonsoubaasdaasansisandasdusanseasnaetiaaus 8 193 oA L92 ao eh EADIE oar ner Meer rt Re er NASE 8 194 8 16 Complex Glazing Database CGDB 00 eee eeeeeeeceneceseeeeeeeeaeeeeeenaeenaeens 8 199 9 SAMPLE PROBLEMS erceciceeticereuctenetcestseetereteeetsclieesamieeienetee
230. ess 4 Tm t File name Save as type WINDOWE Databases mdb Figure 7 13 Creating a Project Database 7 16 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 8 SPECIAL CASES 8 1 Overview The following special cases are covered in this section 8 2 Meeting Rails page 8 2 8 3 Dividers page 8 10 8 4 Storm Windows page 8 45 8 5 Skylights page 8 57 8 6 Doors page 8 73 8 7 Spacers page 8 74 8 8 Non Continuous Thermal Bridge Elements page 8 77 8 9 Site Built Fenestration Products Curtain Walls Window Walls and Sloped Glazing page 8 90 8 10 Garage Rolling Doors page 8 104 8 11 Creating a Laminate in Optics for NFRC page 8 117 8 12 Creating an Applied Film Layer in Optics for NFRC Certification page 8 131 8 13 Framed Intermediate Pane page 8 141 8 14 Venetian Blinds Between Glass Integral page 8 144 8 15 Frits page 8 192 8 16 Complex Glazing Database page 8 199 THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 1 8 SPECIAL CASES 8 2 Meeting Rails 8 2 Meeting Rails Meeting rail cross sections are the stiles or rails that meet in the middle of a sliding window In this manual the term meeting rail is used generically to describe meeting rails meeting stiles interlock stiles interlocking stiles sliding stiles check rails and check stiles 8 2 1 Modeling Meeting Rails When modeling a meeting rail both the sashes and their associated glazing systems are modeled Fig
231. essfully addressed over the years with a variety of manufacturing techniques and material selections When double glass units first came on the market the two glass layers were often fused around the perimeter to make a permanently sealed air space In recent years however spacers and polymer sealants have largely replaced glass to glass seals and have proven sufficiently durable for residential applications The layers of glass are separated by and adhere to a spacer and the sealant which forms a gas and moisture barrier is applied around the entire perimeter Normally the spacer contains a desiccant material to absorb any residual moisture that may remain in the air space after manufacture Sealed insulating glass units are now a mature well proven technology Designs utilizing high quality sealants and manufactured with good quality control should last for decades without seal failure 2 6 4 Glass Coatings and Tints in Double Glazing Both solar reflective coatings and tints on double glazed fenestration products are effective in reducing summer heat gain however only certain coatings contribute to reducing winter heat loss and tints do not affect the heat loss rates at all It is possible to provide reflective coatings on any one of the four surfaces although they are usually located on the outermost surface or on the surfaces facing the air space Coating location can also depend on the type of coating Some vacuum deposited reflective c
232. est disadvantage of aluminum as a fenestration product frame material is its high thermal conductance It readily conducts heat greatly raising the overall U factor of a fenestration unit Because of its high thermal conductance the thermal resistance of an aluminum frame is determined more by the amount of surface area of the frame than by the thickness or the projected area as with other frame materials Thus an aluminum frame profile with a simple compact shape will perform much better than a profile with many fins and undulations In cold climates a simple aluminum frame can easily become cold enough to condense moisture or frost on the inside surfaces of fenestration product frames Even more than the problem of heat loss the condensation problem spurred development of a more insulating aluminum frame The most common solution to the heat conduction problem of aluminum frames is to provide a thermal break by splitting the frame components into interior and exterior pieces and use a less conductive material 2 4 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 2 FENESTRATION PRODUCTS 2 5 Basic Glazing Materials to join them There are many designs available for thermally broken aluminum frames The most prevalent technique used in residential fenestration products is called pouring and debridging The frame is first extruded as a single piece with a hollow trough in the middle This is filled with a plastic that hardens into a
233. et Wavelength set truncated to 0 300 2 500 um This message does not indicate a problem because the solar optical properties in WINDOW are calculated between 0 300 and 2 500 um if Optics let m x Eile Edit Database View Tools Graph Help Cy Ce AESC Main Database IGDB Glazing System Laminate 4 Add Glazing Add Interlayer Add Embedded Coating Edit Laminate view All Schematic Warnings Layer 1 H2 H3 Filename CLEAR BLUGR Petes fh TUM T la 0 715 o 0035 0869 102Bluegreen dup 9811 usr Laminate SPF T f 0 555 139 546 2 512 Results could not be calculated at all wavelengths in the selected wavelength set TOW T Iooae Ine26 0 897 Wavelength set truncated to 0 300 2 500 ym EmitF 0840 0000 0 840 Emith og40 o 000 0 840 I CalcLamusr 2 W5_NFRC_2003 IGDB version 14 5 Figure 8 113 An example of a warning that is not relevant for the calculations WINDOW will be doing with the laminate 8 11 3 14 Save the Laminate to a User Database to Import into WINDOW5 User databases have the same format as the IGDB but they are used to store data that the user has imported or generated with Optics It is not possible to add layers to the IGDB so all new layers are saved to the user database The default user database is UserGlazing mdb in the LBNL Shared directory of your program installation You can specify the location of the user database this allows you to use a
234. ete O O w bd 10 records found 3 ne E Import Export Step 3 The selected record will be Report imported into the library ddad Print b El For Help press F1 Mode NFRC sI NUM SCRL g Figure 8 39 Import the THERM file into the WINDOW Divider Library 10 Use the new divider in the calculation of the complete product values in the main screen of WINDOW THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 38 8 SPECIAL CASES 8 3 Dividers 8 3 4 Door Caming When modeling glazing options with caming which are treated in a similar fashion to dividers the NFRC default caming can be used The flat caming H Bar shall be used as the default shape Brass conductivity and emissivity per NFRC 101 Appendix B shall be used as the default material The caming drawing DXF file is available from the NFRC website XY MAT A BRASS INC FULL SCALE C BRUSHED NICKEL H ROUND D BLACK NICKEL H FLAT REFERENCE 030803 NOTE FOR CRYSTAL DIAMONDS LITES H FLAT BRASS CAMING IS DESIGNATED BY A 1A IN THE PARTE Figure 8 40 Standardized Caming Drawing Decorative caming between two pieces of glass is an exception to the rules for linking frame cavities to glazing cavities as discussed in Chapter 6 This type of caming is only modeled if the distance between the exterior sides of the caming and the inside surface of the glazing system are less than 3 mm Therefore even for contoured caming sh
235. etermine what happens to solar gain 3 4 1 Determining Solar Heat Gain There are two means of indicating the amount of solar radiation that passes through a fenestration product These are solar heat gain coefficient GHGC and shading coefficient SC In both cases the solar heat gain is the combination of directly transmitted radiation and the inward flowing portion of absorbed radiation Figure 3 3 However SHGC and SC have a different basis for comparison or reference The SHGC value is calculated for NFRC rating and certification SHGC replaces SC because it more correctly accounts for angle dependent effects SC represents the ratio of solar heat gain through the system relative to that through 3 mm 1 8 inch clear glass at normal incidence THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 3 5 3 4 Solar Heat Gain and Visible Transmittance 3 FENESTRATION HEAT TRANSFER BASICS Double glazed window Solar transmittance Reflected gt radiation Absorbed radiation OUTDOORS I INDOORS a aa Oe E on o a Inward flowing component of absorbed radiation Figure 3 3 A glazing system s properties of reflection transmission and absorption determine what happens to solar gain 3 4 2 Solar Heat Gain Coefficient SHGC The solar heat gain coefficient SHGC represents the solar heat gain through the fenestration system relative to the incident solar radiation Although SHGC can be determi
236. ew Layers 2 F Tilt 20 IG Height 1000 mm Copy Environmental FRc 100 2010 m IG width 1000 mm Delete Comment FO 2 Overall thickness 16 596 mm Mode ha Save Report ID Mame Mode Thick Flip Tsol Asoll Reol Twie Ayvisl Awisz Tir E Ez Cond Glass 1 He 102 CLEAR_3 DAT 30 0834 0 075 0 075 0 699 0 083 0 083 0000 0 840 0840 1 000 Gapi 1 ir Glass 2 ee 102 CLEAR_3 DAT 30 0834 0 075 0075 0899 0 083 0 083 0o00 O840 0 840 1 000 EEE me te Bees esse Beor Center of Glass Results Temperature Data Optical Data Angular Data Color Properties Ufactor SIE SHG Rel Ht Gain TWh re F Ww frie 3 2204 0 5794 0 7650 od Ea For Help press Fl Mode NFRC Sr uum 2 Figure 8 60 Make new glazing system in the Glazing System Library with Tilt 20 degrees 2 Save the file Make sure to save the glazing system Record menu Save choice THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 60 8 SPECIAL CASES 8 5 Skylights In THERM for Sill 1 Draw the appropriate cross sections for the Sill THERM 6 3 SL NoGlazing THM E Ioj x cs File Edit View Draw Libraries Options Calculation Window Help a x Rectangle F3 OGE Sli Povar 2 fraQ aoiei eulky Boundary Conditions F10 Fill void Insert Point Shiht F Delete Point Del Edit Points Move Polygon Fil Tape Measure Fa Set Drawing Scale shift F amp Set Origin Shifk F Step 1 SSS SSS Click on
237. ffects of conduction convection and radiation This is indicated in terms of the U factor of a fenestration assembly Solar Gain Regardless of outside temperature heat can be gained through fenestration products by direct or indirect solar radiation The amount of heat gain through products is measured in terms of the solar heat gain coefficient GHGC of the glazing Infiltration Heat loss and gain also occur by infiltration through cracks in the fenestration assembly This effect is measured in terms of the amount of air cubic feet or meters per minute that passes through a unit area of fenestration product square foot or meter under given pressure conditions In reality infiltration varies with wind driven and temperature driven pressure changes Infiltration also contributes to summer cooling loads in some climates by raising the interior humidity level The 2001 ASHRAE Handbook of Fundamentals contains the following equation for calculating the energy flow through a fenestration product assuming no humidity difference and excluding air infiltration q U Apf tout tin T SHGC Apr Er 3 1 Where g instantaneous energy flow W Btu h U overall coefficient of heat transfer U factor W m K Btu h ft F tin interior air temperature C F tout exterior air temperature C F Ap Total projected area of fenestration m ft SHGC overall solar heat gain coefficient non dimensional E i
238. fine the window THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 191 8 SPECIAL CASES 8 15 Frits 8 15 Frits WINDOW 6 has the ability to model fritted glazing layers At this time it is not possible to model frits applied to coated substrates Frits are a ceramic surface treatment that is baked onto the surface of a piece of glass called a substrate The ceramic frit has the optical characteric that the incident light passing through it has both a specular component that goes straight through the construction and a diffuse component that scatters the light in many different directions This means that in order to model it correctly it is necessary to measure both those different optical characteristics Frit Substrate Diffuse Incident Light front back Figure 8 179 Ceramic frits have both a diffuse and specular optical properties component In order for WINDOW 6 to model the optical and thermal properties of the fritted glass the program must have the following data 1 Spectral data for the substrate covered 100 by the frit 2 Spectral data for the substrate by itself Then to define a specific frit pattern the user specifies the percent coverage of the frit on the substrate 1 Spectral data for the substrate covered 100 by the frit For specular glass the transmittance is the same for the front and back surface and the reflectance values are different However to obtain data for the first case above
239. fined nine regions within a door that need to be modeled These regions include Frame Area Lite Frame Area Divider area Edge of divider area Edge of Lite Area Center of lite area Door Core Area Panel Area Edge of Panel Area NFRC 100 contains several figures which illustrate the location of the door sections to be modeled in THERM When modeling glazing options with caming the NFRC default caming can be used A spreadsheet must be used to do the door area weighting from the THERM files because the current version of WINDOW does not area weight doors In THERM the U factor Surface Tags can have any name and as many U factor Surface Tags can be defined as are needed to accurately describe the model See Section 6 2 4 Define U factor Surface Tags in the THERM User s Manual so define as many U factor Surface Tags as needed and name them descriptively 8 10 1 Sectional Garage Door Insulated and Non Insulated The overall product U factor is calculated based on the area weighted average of the U factor of each component of the door The components used for area weighting a sectional garage door are Top Rail Bottom Rail End Stile Meeting Rail Door Panel Core Edge of Lite Center of Lite The U factor of each component is calculated using two dimensional heat transfer software THERM The sectional garage doors with embossed or raised panels are not covered in this section However refer to the
240. flow without actually opening the window Operable skylights or vents allow hot air that rises to the ceiling level to be effectively exhausted from the space Skylights and roof windows present a special case for insulating around windows because they are typically set into the thickest most heavily insulated framing in the house and they must also meet much more stringent conditions for shedding water In order to create a positive water flow around them skylights are commonly mounted on curbs set above the roof plane These curbs rising 15 to 30 centimeters 6 to 12 2 2 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 2 FENESTRATION PRODUCTS 2 3 Performance Implications of Basic Fenestration Types inches above the roof create additional heat loss surfaces right where the warmest air of the house tends to collect Ideally they should be insulated to the same level as the roof In practice it is often difficult to achieve insulation levels much above R 11 Some manufacturers provide curbs prefabricated out of a rigid insulating foam which can be further insulated at the site Roof windows mounted in a sloping roof often include a metal flashing system If this metal flashing is in contact with a metal window frame it can create additional surfaces for conducting heat Thus as with thermally broken aluminum windows care should be taken to ensure a thermal separation between the cold outer metal surfaces and metal parts of the
241. g _ THERM 6 3 DividerContoured THM Oj x E File Edit view Draw Libraries Options Calculation Window Help i z i ox al OoeEs hosteadrphLaQgsz oa g insert Glazing Systern x Orientation Down OF Click on the Add as Cancel additional glazing Glazing system width 21 mm system radio button in CR cavity height 1000 mm the Insert Glazing Sight line to bottom of glass E mm Set Sight line to System dialog box Spacer height 0 mm bottom of glass and Edge of Glass Dimension 63 5 rar Spacer height to Glazing system height 1 50 mm ZETO Insert Glazing System x Replace Existing Glazing System Sight line to shade edge lo mm Add as additional glazing system Cancel W Use nominal glass thickness Use CR Model for Window Glazing Systems Gap Properties i Default Custom Gap eff O 09S025 Wlmek width 15mm 2 Glazing System Spacer Draw spacer Single spacer for multiple glazings Maternal Fiberglass PE Resin s Default Boundary Conditions i Use U factor values 0 Use SHGC values x 323 8 175 1 dx dy 301 2 133 4 len 329 4 Step 10 0 mm Risady Exterior Boundary Condition Interior Boundary Condition Use existing BC from library select below Use convection plus enclosure radiation ka NFRC 100 207 0 Exterior al Figure 8 13 Import the second glazing system as an additional glazing system facing down THERM6 3 WINDOW6 3 NFRC Simu
242. g element using the formula Rt X D k Equation 2 Where Rt Sum of the thermal resistances of the individual non thermal bridging material Units m K W SI or hr ft F Btu IP D Depth of the individual non thermal bridging elements that will be substituted by the calculated effective conductivity Units m SI or ft IP or in alternate IP k conductivity of the individual non thermal bridging elements that will be substituted Units W m K SI or Btu hr in F IP or Btu in hr ft F alternate IP Therefore Kn Dt Rt Equation 3 Where Dt Total depth which is the sum of the depths of the individual non thermal bridging elements Calculate the fraction of thermal bridging material to non thermal bridging material as follows Fb Wb Sb Fb Fb 100 Equation 4 Fn 1 Fb Equation 5 THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 79 8 SPECIAL CASES 8 8 Non Continuous Thermal Bridge Elements Where Wb Bridging material width Sb Bridging material spacing 8 8 5 Example 1 Bolts in Curtain Wall Note This example is only presented in SI units and is not translated into IP units The following figures show two cross sections of the curtain wall in Figure 8 78 Figure 8 80 represents the cross section of the curtain wall where the bolt occurs screw threads should be averaged and not drawn explicitly and Figure 8 79 represents the cross section of the curtain wall where the bolt does not occur
243. g layers in a glazing system do not have a spectral data file WINDOW assumes a flat spectral behavior of the glazings without the spectral data files based on their stated visible and solar properties For NFRC certification simulation the NFRC approved spectral data files must be used indicated by a symbol in the WINDOW Glass Library THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 4 3 4 3 THERM Computational Methods 4 SUMMARY OF ALGORITHMS 4 3 THERM Computational Methods THERM incorporates a two dimensional heat transfer model utilizing a finite element method to numerically solve the governing two dimensional energy equation The geometry of the fenestration system consists of the frame and glazing sections where glazing materials are transferred from the WINDOW program Frame materials are directly assigned in the THERM program and the appropriate boundary conditions are applied on the frame surfaces exposed to indoor room air and outdoor air while the bottom frame surfaces and the top of glazing surfaces are assigned adiabatic boundary conditions The numerical model needs to have boundary conditions assigned to each boundary surface of the model in order to be completely defined Boundary conditions on indoor and outdoor surfaces consist of both a convection and radiation component The convection component on the indoor side is specified through the use of a temperature dependent surface heat transfer coefficient based on natur
244. g matrix that is to be simulated for this window However for this example only Glazing Option 1 will be modeled using CIG glass Table 9 8 Matrix of glazing options for the aluminum horizontal slider m Glazing Options e 25 4 mm 1 0 overall thickness Grid Option Clear 3mm Argon 95 Low E 3mm Argon 95 Low E 5mm Not modeled 95 Low E 6mm Not modeled 95 4mm 95 9mm Clear 6mm Argon 95 Clear 8mm Argon 95 Low E 3mm 95 4mm 95 5mm 6mm 6 Clear 4mm Argon 95 Low E 4mm Not modeled Clear 5mm Argon 95 Low E 5mm Not modeled 8 Clear 6mm Argon 95 Low E 6mm Not modeled 9 3 3 Center of glazing Modeling WINDOW In WINDOW create the glazing systems needed for the Glazing Matrix in Section 9 3 2 The figure below shows the record for Glazing Option 1 in the Glazing System Library se Glazing System Library C Program Files LENL WINDOW63 4luminum Slider mdb i ioj x File Edit Libraries Record Tools wiew Help WER EaR T OF 7 ra R Glazing System Library List Dei Name 3mm CIG New Layers a E Tilt 30 5 IG Height 1000 mm Copy EnvronmentA ERC 100 2010 m IG width 1000 mm Delete Comment Do O O Save Overall thickness 25 400 mim Mode jt ID Mame Mode Thick Flip Tsol Reoll Raol Tvis Avisl Awis Tir E E2 Cond Glass 1i 2001 CLA 3 CIG 30 0 848 0 076 0 076 0 904 0082 0082 0 0
245. g problems during the simulation because of too much detail Once all the circled areas in the drawing have been examined press the Boundary Conditions toolbar again if the program identifies bad points but you wish to keep the detail just click OK and the boundary conditions will be generated Having THERM adjust the points is an all or nothing proposition which is why all the points should be examined first before having the program adjust them Also keep in mind that the automatic fixing of points cannot be reversed by THERM There are points in the model that are closer together than the program tolerance What would you like to do Automatically adjust points within tolerance f Mark the points but don t adjust them Cancel Figure 6 31 Message when trying to define boundary conditions indicating that there is a problem in the geometry The best way to fix points that are too close together is to delete or move the offending point Many times the point in question is in all the adjacent polygons so it is best to delete the point in all the polygons at the same time by selecting all the polygons using the Shift key then delete the point it will be deleted from all the selected polygons THERM also marks Voids and Overlaps by checking for lonely edges two adjacent edges with a different number of points on each edge THERM marks voids and overlapping polygons with red circles also One way to eliminate the
246. g to Frame For the interior frame from midpoint to the top sightline set the Boundary Condition to lt frame type gt Interior Convection Only and the U factor Surface tag to None Interior Glazing Set the Boundary Conditions for each glazing system of the bottom of the glass to lt glazing system gt U factor Inside Film and the U factor Surface tag to Edge for the first 63 5 mm 2 5 inches from the sightline and None for the remainder of the glazing system Exterior Frame For the exterior frame from the midpoint to the bottom sightline set the BoundaryCondition to NFRC 100 2010 Exterior and the U factor Surface tag to SHGC Exterior For the exterior frame from the midpoint to the top sightline set the BoundaryCondition to NFRC 100 2010 Exterior and the U factor Surface tag to None Exterior Glazing Set the BoundaryCondition to NFRC 100 2010 Exterior and the U factor Surface tag to None for both exterior glazing systems THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 100 8 SPECIAL CASES 8 9 Site Built fenestration products Curtain Walls Window Walls and Sloped Glazing Head Exterior Interior 150 mm 6 0 inches BC lt glazing system gt U factor Inside Film Radiation Model AutoEnclosure BC NFRC 100 2010 Exterior U factor tag None Radiation Model Blackbody U factor tag None 63 5 mm 2 5 inches
247. gap between glass layers there is always a mixture of the gas and air The amount of air mixed in is dependent on many factors including the method used to fill the gap either evacuated chamber filling two probe filling with a concentration sensor or single probe timed filling Table 5 3 shows the maximum gas concentrations that can be achieved with each method For NFRC certification simulations the simulator shall request the gas filling technique and the gas concentration for their product from the manufacturer Table 5 3 Gas Concentrations based on Filling Technique Maximum Gas Concentrations Achieved 95 for Argon filled 90 for any other gas Krypton Xenon etc 60 90 For IG units with multiple gases the simulation shall be performed using the gas concentrations stipulated by the manufacturer but in no case can the simulation exceed the Maximum Gas Concentration shown in table 5 3 for the fill technique used In the case where the fill technique is Two Probe with concentration sensor and the gas mix is Krypton amp Argon the Maximum Gas Concentration of the mixed gas shall not exceed 90 HH W6 3 Gas Library C Users Public LBNL WINDOW6 w6 mdb File Edit Libraries Record Tools View Help I Bale li oOo z Type Conductivity Viscosity Density Prandtl Wi mE kg m kg m 0 024069 Argon 0 016345 0 000021 521 929016 1 781832 Krypton 0 008664 0 000023 248 091003 3 737 796 enon 0 005760 0 000021 158 339996
248. genic mdb Browse Optics 5 User database C Users Public LENL LBNL Shared UserGlazing Browse Standards File C Program Files amp 6 LENL LBNL Shared Standa Browse Figure 8 119 Using the File Preferences menu click on the radio button for the Optics User database and use the Browse button to specify the file with the full directory path In WINDOWS go to the Glass Library List View click on the Import button select IGDB or Optics User Database as the format and click OK v Avoid creating duplicate records in export database by searching for identical records Cancel Figure 8 120 Import the data from the Optics User Database The program will open the user database set in the File Preferences dialog box the name will be displayed at the top of the dialog box and you will see the glass layers that can be imported in to the existing library E C Program Files LBNL Optics5 hb3 mdb 7 xl Cancel Select All Clear selection Find fib i records found NFRC_ID FileName ProductName Manufacturer Acceptance Thickness ef Appearance Conductivity Database_Version Wem K gt eva quamarine 9811 usr 0 82 User Figure 8 121 You will see all the entries in the specified user database You can select the records you want to import use Shift Click to select contiguous records Ctl Click to select multiple non contiguous records or Select All to select all records Then click the Select
249. ghting a rolling door are Top Rail Bottom Rail End Stile Door Core The U factor of each component is calculated using two dimensional heat transfer software THERM The boundary condition details and other modeling assumptions used on the simulation models for door components are discussed in the following sections THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 111 8 SPECIAL CASES 8 10 Garage Rolling Doors 8 10 2 1 Top Rail Model A nominal 2x4 wood block is used in the Top Rail Model as shown in the figure below The torsion spring assembly and any non continuous hardware shall not be included in this model The boundary conditions BC and U factor tags used in the model are described in the figure below THERM File Properties Cross section Type Head Gravity Arrow Down BC Adiabatic U Factor Surface tag None BC Interior lt frame type gt convection only Radiation Model Blackbody U Factor Surface tag Frame BC NFRC 100 2010 Exterior Radiation Model Blackbody U Factor Surface tag SHGC Exterior t BC Adiabatic U Factor Surface tag None Figure 8 105 Top Rail Model for Rolling Door THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 112 8 SPECIAL CASES 8 10 Garage Rolling Doors 8 10 2 2 Bottom Rail Model A nominal 2 x 6 wood block is used in the bottom rail model of the rolling door The figure below illustrates the boundary conditions and U factor
250. glass enter 0 84 for the emissivity of the front and back surfaces c Ifthe sample is not glass then the emissivity of the material shall be determined per the applicable ASTM standard d The solar visible and Tir spectral data values shall not be used and therefore the default values shown do not need to be modified 4 Build the glazing system to be used in the THERM model in the Glazing System Library 5 Import the glazing system into the applicable THERM model Glass Block Example The Cs value from the ASTM C1363 test 0 635 Btu hr ft2 F The glass 1 008 thick Keffglass 0 635 1 008 12 0 0533 Btu hr ft F 0 092 W m K 3 Inthe Glass Library make a new record and set the Conducivity to 0 092 W m K Set the front and back emissivity to 0 84 THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 70 8 SPECIAL CASES 8 5 Skylights a Window Library C Program Files LBNL WINDOW63 Skylight mdb l E x File Edit Libraries Record Tools View Help DSH t eelml herp n Bla OM OHF List Glass Library In 20000 Thickness 25 6 mm Optics 5 Name Glass Block N Product Name Copy Manufacturer Generic Delete Solar Trans Front Tso 0 834 Save Trans Back Tsol2 0 834 Reflect Front Rsol1 0 075 Reflect Back Rsol2 0 075 m Visible Trans Front T vis 0 899 Trans Back T vis2 0 899 Reflect Front Awist 0 083 Reflect Back Rvis2 0 083 IR T
251. glazing system at which time they must be rotated 90 degrees For heads the glass should face down for sills and jambs the glass should face up with the inside surfaces of the model facing to the right and the exterior surfaces facing to the left The jamb fixed jamb vent and meeting rail cross sections can be drawn horizontally as in the DXF file until the glazing system is to be imported At that time rotate the cross section 90 degrees so that the glazing systems will point up or up and down in the case of the meeting rail Figure 6 3 DXF file with horizontal cross sections that must be rotated 90 degrees before importing glazing systems and simulating THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 6 5 6 3 Draw the Cross Sections 6 MODELING FRAME AND EDGE HEAT TRANSFER WITH THERM bs De orana E j8 10 x THERM Jf_01 thm yy 7B 10 x M Ele Edt wiew Draw Libraries Options Calculation Window Help 18 x B File Edt View Draw Libraries Options Calculation Window Help la x OSE S4iBiboe tia irL agol l Feul Cee SlB Lo sstiayrlraQqggsed amp F eul shou creen Jamb Cross Section Glass orientation Up Cross section type Jamb Gravity Arrow Into screen Head Cross Section Glass orientation Down Gravity Arrow Down Cross section type Head Sai Yv E gt gt x y 2 249 9 395 dx dy 3 641 10 855 llen 11 450 Step 0 394
252. glazing system of the top of the glass to lt glazing system gt U factor Inside Film and the U factor Surface tag to Edge for the first 63 5 mm 2 5 inches from the sightline and None for the remainder of the glazing system Exterior Frame For the exterior frame from the midpoint to the top sightline set the BoundaryCondition to NFRC 100 2010 Exterior and the U factor Surface tag to SHGC Exterior For the exterior frame from the midpoint to the bottom sightline set the BoundaryCondition to NFRC 100 2010 Exterior and the U factor Surface tag to None Exterior Glazing Set the BoundaryCondition to NFRC 100 2010 Exterior and the U factor Surface tag to None for both exterior glazing systems THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 102 8 SPECIAL CASES 8 9 Site Built fenestration products Curtain Walls Window Walls and Sloped Glazing Sill Exterior Interior 150 mm 6 0 inches BC lt glazing system gt U factor Inside Film Radiation Model AutoEnclosure U factor tag None BC NFRC 100 2010 Exterior Radiation Model Blackbody U factor tag None 63 5 mm BC lt glazing system gt U factor Inside Film 2 5 inches Radiation Model AutoEnclosure U factor tag Edge BC NFRC 100 2010 Exterior _ Gg BC Interior lt frame type gt Convection only Radiation Model Blackbody Radiation Model AutoEnclosure U factor tag SHGC Exterior U f
253. h a hole at the edge of the unit As the gas is pumped in it mixes with the air making it difficult to achieve 100 percent purity Recent research indicates that 90 percent is the typical concentration achieved by manufacturers today Some manufacturers are able to consistently achieve better than 95 percent gas fill by using a vacuum chamber An uncoated double pane unit filled with 90 percent argon gas and 10 percent air yields a slightly more than 5 percent improvement in the insulating value at the center of the glass compared to the same unit filled with air However when argon and krypton fills are combined with Low E coatings and multipane glazings more significant reductions of 15 to 20 percent can be achieved Since the Low E coating has substantially reduced the radiation component of heat loss the gas fill now has a greater proportional effect on the remaining heat transfer by convection and conduction THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 2 13 2 7 Thermally Improved Edge Spacers 2 FENESTRATION PRODUCTS 2 Thermally Improved Edge Spacers The layers of glazing in an insulating glass IG unit must be held apart at the appropriate distance by spacers The spacer system must provide a number of additional functions in addition to keeping the glass units at the proper dimension accommodate stress induced by thermal expansion and pressure differences provide a moisture barrier that prevents passage of water or wate
254. h file The options are either that the program will append the Glazing System ID as a 3 character number such as 001 002 or Name to the base case filename 5 Boundary Conditions THERM will automatically calculate the boundary conditions for each separate glazing system option THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 6 19 6 4 Importing Glazing Systems 6 MODELING FRAME AND EDGE HEAT TRANSFER WITH THERM Glazing System Options xX Base Glazing System 8 Sample Glzoys ach of the following glazing systems will be uze eate 4 separate simulation with the same tra Click on the Add button in the Glazing System Options dialog box Name the Therm files based on Glazing system name Glazing system ID Example sample sill_008 thm The Add Glazing Option dialog gt x box shows all the glazing systems which match the Base Glazing i pines eee System in terms of glass layer ee thickness and overall thickness Select All Select individual glazing systems use Shift click and Ctrl click or click on Select All and click the OK button WINDOW Glazing System Library E Program Files LENLAWINDOWESY Browse Click on the Browse to select a different WINDOW Glazing Svstem Librarv Glazing System Options x Base Glazing System 6 Sample GleSys OF When simulating each of the following glazing The selected Glazing Systems svsteme will be uted to create a separate simulation
255. h for a glass sliding door the selection of high performance glass can have significant benefits 2 2 4 French Doors and Folding Patio Doors French doors and folding glazed doors are growing in popularity A basic double French door consists of two hinged doors with no center mullion resulting in a 1 5 to 1 8 m 5 to 6 foot wide opening Folding doors are typically made of pairs of hinged doors so that a double folding door with two pairs of doors can create an opening of 3 7 m 12 feet or more 2 2 5 Skylights and Roof Windows The vast majority of skylights are permanently fixed in place mounted on a curb above a flat or sloped roof However hatch style skylights that can be opened with an extended crank push latch or remote control motor are becoming more common Some skylights have a domed profile made of one or two layers of tinted or diffusing plastic A roof window is a hybrid between a skylight and a standard window They have become increasingly popular as homeowners and designers seek to better utilize space in smaller houses by creating habitable rooms under sloping roofs They are glazed with glass rather than plastic and are available with most of the glazing and solar control options of standard windows Both fixed and operable versions are available and the operable roof windows can be opened manually or by a motorized system In addition some manufacturers offer special venting mechanisms that allow some ventilation air
256. hall include two full slats and two half slats at each end The details of the section where slats join shall be obtained from the manufacturer The boundary conditions on door core model are specified in the figure below THERM File Properties Cross section Type Horizontal Meeting Rail Gravity Arrow Down THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 115 8 SPECIAL CASES 8 10 Garage Rolling Doors BC Adiabatic U Factor Surface tag None gt BC NFRC 100 2010 Exterior Radiation Model Blackbody BC Interior lt frame type gt convection only i i Radiation Model Blackbody U Factor Surface tag SHGC Exterior U Factor Surfacetag Core 7 BC Adiabatic U Factor Surface tag None Figure 8 106 Door Core Model for Rolling Door THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 116 8 SPECIAL CASES 8 11 Creating a Laminate in Optics for NFRC 8 11 Creating a Laminate in Optics for NFRC 8 11 1 Overview Optics can be used for the limited purpose of constructing laminates for NFRC certified simulations using the following criteria Laminates cannot have embedded coatings where embedded coatings are defined as a coating ona substrate that touches an interlayer Only NFRC glass layers with the NFRC approval indicator can be used in these constructed laminates The glass layers can be tinted or coated as long as the coatings do not face the interlayer The
257. han 5 mm so the smaller cavity can be linked to the larger cavity See Section 6 4 4 for details about linking cavities to glazing cavities iE THERM 6 3 Stormwindow sill thm if File Edit View Draw Options Calculation Window Help D eS amp Lb c Set Material F4 U Stormwindow sill Storm Window Cavity 2 Set Boundary Condition F5 Material Library Shift F4 Boundary Condition Library Shift F5 Gas Library Shift F6 Select Material Boundary Condition Glazing Systems F6 UFactor Names J Create Link Cavity width 25 695 mm Remove Link Step 2 Because it is greater than 5 Click on the mm it can be linked to the Libraries Create Link glazing cavity menu choice The cursor will become an eyedropper Click the eyedropper on the glazing system cavity which is the material the Step 1 first polygon will be Fill the space below the linked to glazing system cavity with any material using the Fill Tool Click on the polygon to select it Figure 8 49 If needed create a material link between the glazing system cavity THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 50 8 SPECIAL CASES 8 4 Storm Windows 5 Generate the Boundary Conditions by pressing the BC toolbar button The figure below shows the boundary conditions for one storm window cross section Make sure that the interior boundary conditions have the Radiation Model set to AutoEnclosure BC Adiabatic U factor tag None
258. have an interior wood element bonded to an exterior fiberglass element 2 5 Basic Glazing Materials Two basic materials are used for fenestration product glazing glass which is by far the most common and plastics which have many specialized applications THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 2 5 2 5 Basic Glazing Materials 2 FENESTRATION PRODUCTS 2 5 1 Glass Traditionally fenestration products have been made of clear glass Most residential grade clear glass today is produced with the float technique in which the glass is floated over a bed of molten tin This provides extremely flat surfaces uniform thicknesses and few if any visual distortions The glass has a slight greenish cast due to iron impurities but this is generally not noticeable except from the edge An even higher quality glass with reduced iron content eliminates the greenness and also provides a higher solar energy transmittance This is commonly called water white glass Obscure glasses still transmit most of the light but break up the view in order to provide privacy This effect is generally achieved either with decorative embossed patterns or with a frosted surface that scatters the light rays By adding various chemicals to glass as it is made glass can be produced in a wide variety of colors Glass colors are typically given trade names but the most frequently used colors can be generally described as clear bronze gray and blue g
259. he error estimate recorded with the U factor results and the program may or may not refine the mesh depending on the result of the Error Energy Norm If an error message is displayed saying that the error energy norm cannot be reached increase the Maximum Iterations value set by default to three iterations An Error Energy Norm of less than 10 is equivalent to an uncertainty of less than 1 in the U factor THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 6 39 6 6 Calculating Results 6 MODELING FRAME AND EDGE HEAT TRANSFER WITH THERM 6 6 3 Required Settings for NFRC Simulations In the THERM File Options tab found in the Options Preferences menu the following values must be set Table 6 5 Options Preferences settings for THERM NFRC modeling Run Error Estimator must be checked SS Preferences Drawing Options Simulation Therm File Options Snap Settings Mesh Control Quad Tree Mesh Parameter E M Run Error Estimator Maximum Error Energy Norm fi 0 4 Maximum Iterations 3 V Use CR Model for Glazing Systems Figure 6 32 NFRC required THERM File Options settings In the Simulation tab found in the Options Preferences menu the Relaxation Parameter can be set to 1 0 and the feature to Automatically adjust relaxation parameter should be set as shown in the figure below Therm File Options Snap Settings Preferences Drawing Options Simulation ConA ad Simulation Convergence T
260. he formation of condensation on the interior surface of the product at a specific set of environmental conditions The CR calculation method is defined in the NFRC 500 Procedure for Determining Fenestration Product Condensation Resistance Values 3 5 3 Outdoor Condensation Under some climate conditions condensation may occur on the exterior glazing surface of a window This is more likely to occur on higher performance windows with low E coatings or films and low conductance gas fills that create very low U factors By preventing heat from escaping from the interior the exterior surfaces of the window approach outside air temperature These exterior temperatures may be below the exterior dew point causing condensation on the exterior glazing surfaces This is most likely to happen when there is a clear night sky still air and high relative humidity in addition to the right temperature conditions Like other dew formed at night exterior window condensation will disappear as surfaces are warmed by the sun It is the excellent thermal performance of well insulated glazing that creates the condition where the outer glazing surface can be cold enough to cause condensation to form 3 5 4 Condensation Between Glazings A more annoying problem can arise with double pane windows which is condensation between the panes Moisture can migrate into the space between the panes of glass and condense on the colder surface of the exterior pane This condensat
261. he geometry of the retracted venetian blind including the length and width of the stacked venetian blind slats and any continuous hardware that holds the blind in place top and bottom 3 In WINDOW make the appropriate glazing system in this case a triple glazed system that represents the double glazed system and a third glazing layer such as an add on panel THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 159 8 SPECIAL CASES 8 14 Venetian Blinds Between Glass Integral 4 Insert the glazing system The example shown below has glazing layers that intersect the frame at two different heights There are numerous methods for modeling this The method shown is to stretch the glazing layers to meet the frame at the appropriate place and this method also necessitates inserting points on the glazing system for the correct boundary conditions segments Another method would be to insert float glass polygons for the glazing layer extensions this method eliminates the need to insert the points in the glazing system for the boundary condition segments In this example the edges of the glazing system intersect the frame at different heights so the glazing layers are stretched to meet the frame Insert the glazing system at the bottom of the venetian blind assembly with Spacer height and sight line to bottom of glass set to 0 Turn on Allow editing of IG polygon in Preferences Drawing Option
262. he innovation and improvement in fenestration products the overall performance of any unit is determined by the complete fenestration product assembly The assembly includes the operating and fixed parts of the product frame as well as associated hardware and accessories These are defined and illustrated at the beginning of this section The next two sections address the different options available for sash operation and new advances in frame materials designed to improve product energy efficiency Proper installation is an important aspect of their performance as well The final section of this chapter discusses other installation issues 2 2 Fenestration Product Sash Operation There are numerous operating types available for fenestration products Traditional operable types include the projected or hinged types such as casement awning and hopper and the sliding types such as double and single hung and horizontal sliding In addition the current market includes storm windows sliding and swinging patio doors skylights and roof mounted i e sloping windows and systems that can be added toa house to create bay or bow windows miniature greenhouses or full sun rooms Casement Horizontal slider Single hung Double hung Figure 2 1 Fenestration Operator Types THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 2 1 2 2 Fenestration Product Sash Operation 2 FENESTRATION PRODUCTS 2 2 1 Projected or Hinged Windows Hinged win
263. he model The program will calculate both U factor results and the Condensation Resistance results if the CR model is checked 3 Import the results into the WINDOW Frame Library and use the file to create the whole product in the Window Library as applicable THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 54 8 SPECIAL CASES 8 4 Storm Windows Emissivity 1 0 Side Open Emissivity glass layer emissivity Side Left Boundary conditions are drawn inside the glazing system cavity when the CR calculation is turned on Emissivity glass layer emissivity Side Right Emissivity emissivity of adjacent material Side Adiabatic Figure 8 54 Red boundary conditions will appear inside the glazing system when the CondensationResistance option is turned on Check the emissivities of each boundary condition THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 55 8 SPECIAL CASES 8 4 Storm Windows 8 4 4 3 Calculate the Total Product Values in WINDOW The following discussion explains how to model the whole product values for the storm window in WINDOW Import the THERM files into the WINDOW Frame Library ce Frame Library C Program Files _LBNL WINDOW63 Storm Window mdb File Edit Libraries Record Tools View Help D W Se Sli n n Baeni Orle Frame Library C Program Files SLENIH D OWES S kori indo mde Detailed View Frame Edge Edge Glazing Pid Uvalue Uvalue Correlation
264. he performance of multiple pane fenestration product assemblies with low emittance coatings and gas fills is described in the following sections 2 10 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 2 FENESTRATION PRODUCTS 2 6 Improved Glazing Products 2 6 9 Low Emittance Coatings The principal mechanism of heat transfer in multilayer glazing is thermal radiation from a warm pane of glass to a cooler pane Coating a glass surface with a low emittance material and facing that coating into the gap between the glass layers blocks a significant amount of this radiant heat transfer thus lowering the total heat flow through the fenestration product The improvement in insulating value due to the Low E coating is roughly equivalent to adding another pane of glass to a multipane unit The solar spectral reflectances of Low E coatings can be manipulated to include specific parts of the visible and infrared spectrum A glazing material can then be designed to optimize energy flows for solar heating daylighting and cooling With conventional clear glazing a significant amount of solar radiation passes through the fenestration product and then heat from objects within the house is reradiated back through the fenestration product For example a glazing design for maximizing solar gains in the winter would ideally allow all of the solar spectrum to pass through but would block the reradiation of heat from the inside of the house The first Low E
265. hed the results specified in the Calc Display Options menu choice will be drawn on the aail o xy 455 6 112 9 dx dy 56 6 65 7 len 86 7 Step 10 0 mm h Ready Divider U Factor results NUM 4 Figure 8 38 Calculate the results 8 Save the file using the File Save As menu choice 9 Import the results to the WINDOW Divider Library as shown below See Section 4 7 3 Importing THERM files in the WINDOW User s Manual for more information about importing THERM files THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 37 8 SPECIAL CASES 8 3 Dividers Divider Library C Program Files LBNL WINDOW63 Dividers mdb ioj x File Edit Libraries Record Tools View Help Dee tS e S Bin r gt nl Baeme OF Divider Library C Program Files LENLE OWES Dividers mdb if E R R Detailed View Edge Uvalue Update Name Source Type Uvalue m mo Oo w Mm AN Se M Copy A A E E a aa as r a E a a e E E E E E E utl Divided ASHRAE M A Ma Delete Wood Divided ASHRAE Suspended BAA MAA Class3 MA Insul Divided ASHRAE Suspended i S tis ASHRAE Suspended MA cok in E Divider Wino Suspended ASHRAE H A Na DividerContoured THM A DividerContouredGasFilled THM SirulatedDividedLite THM SimulatedD widedLite THM Therm Yertical Divider E ai TrueDividedLite THM DividerContoured THM Therm Yertical Divider 1 9 Advanced 9 records found DrviderContou
266. height per Table 6 2 Section 6 4 5 THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 8 8 SPECIAL CASES 8 2 Meeting Rails 2 Simulate the model The program will calculate both U factor results and the Condensation Resistance results 3 Import the results into the WINDOW Frame Library and use the meeting rail file to create the whole product in the Window Library as applicable Figure 8 11 Red boundary conditions will appear inside the glazing system when the Condensation Resistance feature is activated 4 Check the emissivities of each of these boundaries Note that Condensation Resistance is only modeled for horizontal meeting rails such as in a double hung window THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 9 8 SPECIAL CASES 8 3 Dividers 8 3 Dividers 8 3 1 Internal Dividers Suspended Grilles The criteria for when dividers are modeled can be found in NFRC 100 Section 1 4 4 Simplifications to a Product Line The discussion below describes the methodologies in WINDOW and THERM for modeling dividers when that criteria is met 8 3 1 1 Modeling Steps The modeling steps in THERM6 and WINDOW6 are the same for all divider shapes and all possible gas fills in contrast to modeling steps in previous versions of THERM Linking Frame Cavities and Glazing Cavities Internal dividers are an exception to the rules for linking frame cavities to glazing cavities as discussed in Chapter 6 Internal divider
267. hese films are measured with a substrate For the purposes of the NFRC Applied Film procedure the only films that can be used are those that were measured with a clear substrate the substrate having the properties of Tsol gt 0 820 and Tvis gt 0 890 Optics can accurately calculate the optical properties of applied films on glass layers as long as the applied films were measured following the guidelines listed below and only applied films submitted with these characteristics will be included in the Approved Applied Films list for use in NFRC certified product calculations 8 12 2 1 IGDB Submittal for Applied Films As discussed in the LBNL document which contains guidelines for submitting data to the IGDB International Glazing Database Data File Format Version 1 4 April 2003 an applied film glazing is an adhesive backed film applied to a Monolithic substrate If the measured data submitted to the IGDB includes the substrate information Optics can apply the film to another substrate This means that in order for an applied film to be added to the Optics Applied Film type and therefore used in making applied film glass layers in Optics the spectral data for the reference substrate to which that applied film was attached is submitted to the IGDB as follows Applied films are measured with transparent glass with a solar transmittance greater than 0 820 Tsol gt 0 820 and a visible transmittance greater than 0
268. ht Sills are the same and Left and Right Jambs are the same June 2013 6 MODELING FRAME AND EDGE HEAT TRANSFER WITH THERM Maximum Cross Sections Head Jamb 1 or 2 Sill Head Fixed or Vent Jamb Fixed amp Vent Sill Fixed amp Vent Meeting Rail Head Fixed amp Vent Jamb Fixed amp Vent Sill Fixed amp Vent Meeting Rail Head Fixed amp Vent Jamb Fixed amp Vent Sill Fixed amp Vent Meeting Rail THERM6 3 WINDOW6 3 NFRC Simulation Manual 6 MODELING FRAME AND EDGE HEAT TRANSFER WITH THERM 6 2 Cross Sections to be Modeled Head Jamb Sill Fixed Max 4 Min 3 cross sections Jamb Projecting Awning Max 4 Min 3 cross sections Casement Max 4 Min 3 cross sections Head He acl Head i Jamb Upper Jamb Lower sill Sill Sill Vertical Slider Horizontal Slider Max 7 Min 5 cross sections Max 7 Min 4 cross sections Figure 6 1 Minimum and maximum cross sections to be modeled based on operator type THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 6 3 6 3 Draw the Cross Sections 6 MODELING FRAME AND EDGE HEAT TRANSFER WITH THERM 6 3 Draw the Cross Sections After the number of cross sections to be modeled has been determined draw them in THERM The Section 5 Drawing Cross Section Geometry in the THERM User s Manual contains detailed instructions about how to draw cross sections This section of the THERM NFRC Simulation Manual contains information pertaining s
269. ht line to bottom of glass ern mm Spacer height f15e5 mm Edge of Glaz Dimension 35 mm Glazing system height jso mm Site line to shade edge jo mm Use nominal glass thickness Use CR Model for Window Glazing Systems Gap Properties f Defaut Custom Gafi Keff 0 082924 wm width 125 mm Spacer Draw spacer Single spacer for multiple glazings Material Fiberglass PE Resin Default Boundary Conditions Use U factor values Use SHGC values Exterior Boundary Condition Use existing BC from library select below NFRC 100 2010 Exterior Check the Use nominal glass thickness to turn on this feature This may be useful for multiple glazing option calculations to ensure that all glazing systems have the Interior Boundary Condition Use convection plus enclosure radiation lol x x Fi pala eull o oo F5 Shift F4 shift F5 Step 1 Shift F Select the Glazing System holce from the Library menu Glazing Systems x ID Name Glazing System 1 Single Clear Ucenter 5 91 WwW frm K MERC Che Thickness E 048 mm Shading layers Hone Close WINDOW Glazing System Library C Program FilesS LENLAWIN DOW ES Browse Window 6 Database E x oome l Step 3 Enter the appropriate values CR cavity height value from Table 6 2 based on product height see Section 6 4 5 Edge of glass 63 5 mm Glazing system height 150
270. hts 5 Import the glazing system into the applicable THERM model and simulate the product 6 Calculate the total product U factor WINDOW should be able to calculate this value but if not then use a spreadsheet to obtain the area weighted U factor 8 5 5 Sloped Glazing Systems with Large Gaps WINDOW can now calculate the Center of Glass correctly for gaps widths greater than 30 mm Therefore there are no special steps required for this situation model it as you would any other sloped skylight THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 72 8 SPECIAL CASES 8 6 Doors 8 6 Doors Swinging entry doors are modeled differently than window products because there are more opaque sections to be modeled in THERM The procedures for modeling doors are included in NFRC 100 and that document should be reviewed in detail before modeling any entry door systems NFRC has defined nine regions within a door that need to be modeled These regions include Frame Area Lite Frame Area Divider area Edge of divider area Edge of Lite Area Center of lite area Door Core Area Panel Area Edge of Panel Area NFRC 100 contains several figures which illustrate the location of the door sections to be modeled in THERM When modeling glazing options with caming the NFRC default caming can be used See the section on Dividers in this chapter for information about modeling caming inside an IG A spreadsheet must be use
271. ibrary C Users Public LBNL WINDOW6 w6 mdb File Edit Libraries Record Tools View Help gt Nisun matl OHE ID 1 Mame Picture Mode NFR Copy Delete Save Type Fixed picture ka gt Width 1200 mm Height 1500 mm Area 1 600 m2 Report Tilt a Environmental Conditions NFRC 100 2010 Dividers Dividers Total Product Results calculated by pressing the Calc button U factor SHGC Solar Heat Gain Coefficient VT Visible Transmittance CR Condensation Resistance SHGC 0 6041 Display mode Moral Total Window Results Click on a component to display characteristics below U factor 2 0103 Ww me F lt 4 See the next section for a detailed description of the information in the SHGC VT Detail button Detail YT 0 6484 CA 49 Detail CR Detail Button a Condensation Index Details Area 30 4AH 504AH i U AH Overall CR 1 800 78 26 49 21 36 37 45 96 CRg 1 271 100 00 87 90 46 53 Ez2 78 CRe 0 305 78 26 49 21 36 37 45 96 CR 0 224 ar 7a 73 86 62 51 71 10 COG 1 1 271 0 0000 0 0018 0 1528 0 0515 Header 0 050 0 0038 0 0234 0 0625 0 0299 Header Edge 0 067 0 0278 0 2023 0 3230 0 1844 Left Jamb 0 062 0 0017 OOF 0 0527 0 0241 Left Jamb Edge 0 086 0 0073 0 1321 0 2634 0 1343 Right Jamb 0 062 0 0017 0 0177 0 0527 0 0241 Right Jamb Edge 0 086 0 0073 0 1321 0 2634 0 1343 Sill 0 050 0 0001 0 0126 0 0428 0 0785 Sill Edge 0 0
272. ic U Factor Surface tag None x U factor delta T Length Wie KE C mm Rotation Frame 2 8372 39 0 42 0624 30 0 Projected in Glass Plane SHGC Exterior 2 6078 39 0 42 0624 90 0 Projected in Glass Plane Edge 3 2705 39 0 63 5 90 0 Projected in Glass Plane 2 Error Energy Morr 5 904 Export Figure 9 51 THERM cross section and U factor results for the door lite cross section 9 58 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 9 SAMPLE PROBLEMS 9 5 Problem 4 Door Door Lite Head BC Adiabatic U Factor Surface tag None 4 E j BC NFRC 100 2010 Exterior Radiation Model Blackbody U Factor Surface tag SHGC Exterior BC Interior Wood Vinyl Frame convection only Radiation Model AutoEnclosure U Factor Surface tag Frame Modeling Assumptions Cross Section Head Gravity Arrow Down BC 3 mm Clear Air Clear U factor Inside Film Radiation Model AutoEnclosure U Factor Surface tag Edge BC NFRC 100 2010 Exterior Radiation Model Blackbody U Factor Surface tag None BC 3 mm Clear Air Clear U factor Inside Film Radiation Model AutoEnclosure U Factor Surface tag None E ti BC Adiabatic U Factor Surface tag None x U factor delta T Length Wi me F mm Rotation C Frame 2 8375 so 42 0624 90 0 Projected in Glass Plane SHGC Exterior 2 6064 so 42 0624 90 0 Projected in Glass Plane Edge 2 2
273. ic U factor tag None Cross Section Type Jamb Gravity Vector Into the Screen f BC 3 mm CIG U factor Inside Film Radiation Model AutoEnclosure U factor tag None BC NFRC 100 2010 Exterior Radiation Model Blackbody U factor tag None BC 3 mm CIG U factor Inside Film Radiation Model AutoEnclosure _ U factor tag Edge J BC Interior Thermally Broken Frame convection only Radiation Model AutoEnclosure U factor taq Frame BC Adiabatic i U factor tag None U factor delta T Length Wi fn K Rotation C mm SHGE Exterior e 208 39 0 53 2379 30 0 Projected in Glass Plane Frame 7 7643 39 0 53 2379 30 0 Projected in Glass Plane Edge 2 0802 39 0 64 6568 30 0 Projected in Glass Plane 5 E t Error Energy Norm E04 abel x Figure 9 18 THERM cross section and U factor results for jamb fixed cross section BC NFRC 100 2010 Exterior Radiation Model Blackbody U factor tag SHGC Exterior Ix THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 9 23 9 3 Problem 2 Aluminum Horizontal Slider Window 9 SAMPLE PROBLEMS Head Vent BC Adiabatic U factor tag None 4 Eon BC Interior Thermally Broken Frame convection only Radiation Model AutoEnclosure U factor taq Frame BC 3 mm CIG U factor Inside Film Radiation Model AutoEnclosure U factor tag Edge BC NFRC 100 2010 Exterior Radiation Model Blackbody U factor t
274. ich components head jamb sill and meeting rail are required to calculate the whole product area weighted values 4 4 1 U factor The whole product area weighted U factor calculation shown below is documented in Section 4 6 3 in NFRC 100 Procedures for Determining Fenestration Product U factors 4 1 E D Ur Ag gt Ua Aa X Ue Ac X Uae Aae X Uc Ac Apf Where U Total product U factor W m K Btu hr ft F Apf Projected fenestration product area m ft Ut Frame U factor W m K Btu hr ft F Af Frame area m ft Ua Divider U factor W m K Btu hr ft F Aa Divider area m ft Ue Edge of glazing U factor W m K Btu hr ft F Ae Edge of glazing area m ft Uae Edge of divider U factor W m K Btu hr ft F Ade Edge of divider Area m ft U Center of glazing U factor W m K Btu hr ft F 46 June2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 4 SUMMARY OF ALGORITHMS 4 4 Total Product Calculations Ac Center of glazing area in ft m7 4 4 2 Solar Heat Gain Coefficient SHGC The total solar heat gain coefficient is determined by an area weighted average of contributions from the transparent and the opaque elements in the fenestration product The SHGC is a function of the solar transmittance the solar absorptances of each layer and the inward flowing fraction of thermal energy The SHGC is calculated for each
275. ick on the Eye Dropper tool click on a boundary segment whose definition is to be duplicated to other segments then click on the boundary segment s which need that boundary condition definition The program will 6 32 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 6 MODELING FRAME AND EDGE HEAT TRANSFER WITH THERM 6 5 Defining Boundary Conditions assign both the boundary condition and U factor tag from the copied segment There is also one level of undo for boundary conditions accessed through the Edit Undo file menu choice The Radiation Model of all interior boundary conditions should be set to Automatic Enclosure Model If for some reason the interior boundary conditions do not have the Radiation Model set to AutoEnclosure double click on the boundary condition to open the Boundary Condition Type dialog box which displays the setting they can be easily changed to that model To change the Radiation Model go to the Boundary Condition Library either through the Library menu Boundary Condition Library choice or by double clicking on a boundary condition segment and clicking on the Boundary Condition Library button In the Boundary Condition Library under the Radiation Model click on the Automatic Enclosure Model radio button THERM 6 3 sample sill THM 7 x oe File Edit View Draw Libraries Options Calculation Window Help _ x Deh SS boe te r Lag 2 e E U sample sill Sample GlzSys I
276. ide Film Radiation Model AutoEnclosure U factor Tag None BC NFRC 100 2001 Exterior U factor Tag None BC lt glazing system name gt U factor Inside Film Radiation Model AutoEnclosure U factor Tag Edge SSS ae BC Interior lt frame type gt Convection only Radiation Model AutoEnclosure U factor Tag Frame _ BC NFRC 100 2001 Exterior U factor Tag SHGC Exterior to BC Adiabatic U factor Tag None Figure 8 176 Define the boundary conditions for Jamb Non Retractable Closed Venetian Blind section Simulate each cross section and save the results THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 189 8 SPECIAL CASES 8 14 Venetian Blinds Between Glass Integral In WINDOW 1 Frame Library Import the THERM files into the Frame Library Frame Library C Thermdoc THERM 6 2 WINDOW 6 2 NFRC Sim Manual 2009 w6 enetian mdb File Edit Libraries Record Tools wiew Help D S W s GB Send Baen OH Z K Pw Frame Library C Thermdoc THERM 6 2 WINDOW 6 2 NFAC Sim Manual Detailed View 2009 w6Venetian mdb Update Frame Edge Edge Glazing Uvalue Uvalue Correlation Thickness Wet We rn K mm Al v break ASHAAE M4 5 E80 H A Class M A Al flush ASHRAAE M A 3 970 MA Class M A Delete Wood ASHFAE 22r Class H A Winyl ASHRAE 1 700 Class VenetianFixed pen Head THM Therm MA Source Type Copy VenetanFixed per Sill THM Therm i MA YenetianF iredi p
277. idges such as skip and debridged systems The effect on the performance of a curtain wall system due to bolts is explained in detail in an ASHRAE paper published in 1998 entitled The Significance of Bolts in the Thermal Performance of Curtain Wall Frames for Glazed Facades by Brent Griffith Elizabeth Finlayson Mehrangiz Yazdanian and Dariush Arasteh The THERM model to be simulated for the final result is one in which the actual materials of the thermal bridging elements are replaced with a user defined material having an effective conductivity which represents the area weighted value that combines the bridging and non bridging elements Figure 8 77 below illustrates an example of a curtain wall system which would require that the thermal bridging elements in this case the bolts be modeled using the isothermal planes method Thermal bridging material depth Cross section A through thermal bridging material bolt Cross section B without thermal bridging material bolt Bolt Head Size Bolt spacing e Figure 8 77 Example of a curtain wall system with regularly spaced bolts which act as thermal bridges THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 77 8 SPECIAL CASES 8 8 Non Continuous Thermal Bridge Elements 8 8 3 Modeling Steps The steps for constructing the final THERM model to be simulated are the following 1 2 Draw the THERM model without the thermal bridging material Determine the co
278. ie the spectral data for the substrate covered 100 by the frit it is necessary to take measurements for four different cases For glass with a frit applied both the transmittance and reflectance values are different for the front and the back surfaces and each of those are different for the diffuse and specular components Therefore it is necessary to measure and obtain spectral data files for each of the four cases Specular spectral data for the front surface e Specular spectral data for the back surface e Diffuse spectral data for the front surface THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 192 8 SPECIAL CASES 8 15 Frits e Diffuse spectral data for the back surface 2 Spectral data for the substrate by itself This is the same type o f spectral data measurement for any specular glass layer and is only one file that contains the values by wavelength for transmittance back and front are the same and front and back reflectance 8 15 1 Modeling Steps The steps for modeling fritted glazing layers are as follows In WINDOW 1 Find the appropriate frit product in the Complex Glazing Database CGDB and import it into the WINDOW Shading Layer Library http windows bl gov software CGDB 2 Input the appropriate frit coverage information in the Shading Layer record 3 Make a glazing system using the Frit layer in the appropriate location in the system In THERM 4 Model the appropriate THERM files with th
279. ight BC Adiabatic U factor tag None BC lt glazing system name gt U factor Inside Film Radiation Model AutoEnclosure U factor tag Edge BC Adiabatic U factor tag None BC lt glazing system name gt U factor Inside Film Radiation Model AutoEnclosure U factor tag None BC Interior 20 tilt lt frame type gt Frame Convection only Radiation Model AutoEnclosure U factor tag Frame Figure 8 66 Boundary condition and U factor tag settings for skylight Head example 5 Simulate the file THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 66 8 SPECIAL CASES 8 5 Skylights 6 Click on the Show U factors button to view the U factors dialog box Make sure that the projection is set to Projected in Glass Plane which will allow the program to calculate the correct projected frame dimensions with a tilted cross section U Factors ee xi U factor delta T Length Wi mE E mm Rotation Frame 4 7955 E 43 0001 zon Projected in Glass Plane SHGC Exterior 51 479 39 0 48 5853 zon Projected in Glass Plane Edge 2 5527 39 0 63 5 20 0 Projected in Glass Plane Error Energy Norm hares Export Figure 8 67 Select the Projected in Glass Plane for the projected frame dimension calculation In THERM for Jamb 1 Create the cross section for the Jamb The steps are similar to modeling the head and sill except for the following Jambs are modeled in the vertical
280. ight Operable fenestration products are necessary for ventilation but they are also more susceptible to air leakage Operable units with low air leakage rates are characterized by good design and high quality construction and weatherstripping They also feature mechanical closures that positively clamp the product shut against the wind For this reason compression seal products such as awning hopper and casement designs are generally more effectively weatherstripped than are sliding seal products Sliding products rely on wiper type weatherstripping which is more subject to wear over time and can be bypassed when it flexes under wind pressure 3 Solar Properties of Glazing Materials Three things happen to solar radiation as it passes through a glazing material Some is transmitted some is reflected and the rest is absorbed These are the three components of solar that determine many of the other energy performance properties of a glazing material such as the solar heat gain coefficient and shading Manipulating the proportion of transmittance reflectance and absorptance for different wavelengths of solar radiation has been the source of much recent innovation in fenestration energy performance Visible light is a small portion of the electromagnetic spectrum see Figure 2 3 Beyond the blues and purples lie ultraviolet radiation and other higher energy short wavelengths from X rays to gamma rays Beyond red light are the near infrared give
281. iles LENLSWINDOWS 5 Layer properties Layer 1 gt ID aso Type Glass Marne CLEARS LOF Thickness 5000 mm nominal Front 0 840 Back 0 540 E missiwities Gas properties Gaj oh Name jst Keff 0049 Wirnek ky 81 9 1218 e e tep 100 mm rea40e76 8 Thickness 16 510 mm Specify additional glazing systems For calulations Shading properties Extenor shade Interior shade The Shading properties section should always have N A for all gt Emissivity modifier MA Nia values because shading systems Convection modifier N A NAA cannot be modeled in THERM for NFRC at this time Figure 6 17 Define multiple glazing options Add glazing options From the Glazing System Options dialog box click on the Add button to see a list of all the glazing systems in the currently selected Glazing System Library that have the same overall thickness and glass layer thickness as the base case glazing system Note Use the nominal glass feature if necessary to make all the glazing systems a uniform thickness Click on the glazing systems in the Add Glazing Options dialog box that are to be associated with this cross section use Shift click or Ctrl click to select multiple glazing systems Click OK when all are selected 4 THERM will make a separate file for each glazing option and in the Glazing System Options dialog box click on the radio button choice to determine how the program will automatically name eac
282. im white Venetian Blind Manufacturer Pela Type Venetian blind horizontal Material 31109 White Venetian Blind Slat whit Effective Openness Fraction 1 000 Venetian Blind Slat width mm E Spacing 120 mm Tilt Tilt angle oT B degrees Blind thickness ms mm Rise 0 838 mm Help Figure 8 191 Set the Tilt as needed to define the slat geometry THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 202 8 SPECIAL CASES Tilt 8 16 Complex Glazing Database CGDB Rather than entering a value for the Tilt angle it is much better to select from the Tilt pulldown list and the program will determine the actual tilt based on the curvature of the blind derived from the Rise value THERM6 3 WINDOW6 3 NFRC Simulation Manual Retracted Open fully open 0 Venetian Blind Slat width 14 8 mm Spacing T i Tilt Tilt angle Closed depending on the direction of the slat curvature either o Closed 90 Venetian Blind Slat width 14 8 mm O E Spacing 12 0 mm n Titt Tit angle 88 a degrees Blind thickness 05 mm Rise 0 838 mm Help o Closed 90 Venetian Blind Slat width N48 mm J ee Spacing 12 0 mm Ti z Tit angle a degrees Blind thickness 05 mm Rise 0 838 mm Help June 2013 8 203 8 SPECIAL CASES 8 16 Complex Glazing Database CGDB 4 Shade Material Library Venetian Blind Records When a record from the CGDB Shading
283. in Front of Glazing Exterior glazing to apply the Back of Glazing Interior Back of Glazing Interior ie film to either Front Replace existing film A or Back Create glazing with two filma K Ok ii Select new film or applied film Ioj x Only select films from Type Applied Films Main Database IGOE Click on the to expand the list Only select Applied Films that V FroductNamne Mominal mim Mominal cir Manutact are on the Approved Applied Film List Film 15 x TE Select new film or applied film Main Database IGOE Type z Pra E E T AR li im m nunn mennnnnnnnnnnnnnennsnnnnsnunnsnnnssnnnnsnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnsnnnnsnnnnsnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnsnnnnannnnsnnnnnnnnnnnnnnnnnnnnnnnunsnnnnnnnnnnnnnnannnnsnnnnnnnnnnnnnnnnnnnnnnnnnnsnnnnnnnnnn Applied Film Wkvip swt VIP by Y Kool ma rn 3 0711 Southwall 1580 jt ite Film a Wh7S swt o ransmission Reflectance ont Refectance back Wavelength microns Figure 8 125 Choose the film to apply THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 136 8 SPECIAL CASES 8 12 Creating an Applied Film Layer in Optics for NFRC Certification ani g Select new film or applied film Main Database IGDB Type z maam hopien SLOVCLOB SWT soise Sele Gr a aaraa iss Appied Fin SLOVCLOB sar soiseseeacr wa NA srisfsoumwa fsa hepten vaos vxooean wa wa aoseaf
284. in detail in the following discussion 8 4 2 1 Create Glazing System in WINDOW 1 Make a glazing system consisting of three layers of glass with the dimensions of the glazing cavity for the first gap and the correct dimension from the glass to the storm window for the second gap W6 Glazing System Library C Program Files LBNL WINDOW63 Storm Window mdb a O x Fie Edit Libraries Record Tools View Help Cee eelam aBa e ll Glazing System Library List Calc F5 ID 3 Name Etom Window New Layers 3 a Tit 90 IG Height 1000 mm Er Environmental NERC 100 2010 iG Width 1000 mm E t Delete Oommen 1 9 3 Overall thickness 72 644 mm Mode Save Eea peara _ New Dee Kea m ea ID Name Mode Thick Flip Taal Asal Avis Ayvise Tir E E Glass 7 ee 102 CLEAR_3 DAT 30 J 0 834 0 075 0 083 0083 0 000 0 840 0 840 Gapl 1 Ait 127 OC Glass 2 ee 102 CLEAR_3 DAT 30 Jj 0834 0 075 0 083 0083 0 000 0 840 0 840 Gapz bb 1 Arr 50 8 CO Glass 3 102 CLEAR_3 DAT 30 0834 0 075 0 083 O 083 0 000 0 840 0 840 Report ey MEE Rel Ht Gain Tvis Keff Gap Keff Gap 2 Kett Wim Cao al ee WW nok 0 6842 511 0 7415 0 1723 0 0633 0 2789 El Mode NFRC 51 NUM SCRL 4 Figure 8 47 Make a triple glazed glazing system with a large gap width between the IG and the storm window For Help press Fl THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 48 8 SPECIAL CASES 8 4 Storm Windows
285. ing Don t show CR waming messages system height in the Preferences dialog box the i Create debug output NFRC default being one meter 1000 mm I Use Nominal Heights Glazing system height 1000 0 mm gferature Data Optical Data Angular Data Color Properties Nominal window height 1000 0 mm W Use Nominal Glass Thickness Display precision 4 Default Frame Absorptance 10 300 y Database integrity check before database close recommended Center of Glass Results Te Ufactor Rel Ht Gain Tvis Ket Wem kK Wem Wonk 1 93149 FIO 0 7407 0 0493 In 1 Name Ficture Mode NFROO l Type Fixed picture gt gt Width 1200 mm Height 1500 mm Area 1 800 m2 Tit 90 Environmental Conditions NFRAC 100 2010 The U value for the glazing system is in the Window Library until the Calc button is clicked because the U value is dependent on the height of the glazing system in the window Total Window Results Click on a component to display characteristics below U factor POW me Glazing System P SHEL Name Sample Glz5ys 7 VT i IL g Ucenter T OW nna K CR Nlayers 2 IL Area 1 271 me SHGC Edge area 0 305 me Vie p Click on a component to display characteristics below U factor 2 0703 We m2 k Glazing System The calculated center of SHGC o 6041 glazing U value in the oa oct Name Sample GleSys el Ee Window Library is ba
286. ings and argon gas fill further reduce condensation potential The triple glazed product with low E coatings has such a warm interior surface that condensation on any interior surfaces may be eliminated if humidity levels are maintained at reasonable levels Condensation for typical glazing oe types occur at points in the following shaded areas on the 90 graph 80 E Triple glazed low E coating a o se 2 6O p E Double glazed low E coating E 50 PE Double glazed 2 40 clear tinted glass S 50 PE Single glazed clear tinted glass 20 Note all air spaces are 1 2 inch all coatings are e 0 10 Outdoor Temperature F Figure 3 4 Condensation potential on glazing center of glazing at various outdoor temperature and indoor relative humidity conditions 3 8 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 3 FENESTRATION HEAT TRANSFER BASICS 3 5 Condensation Resistance Condensation forms at the coldest locations such as the lower corners or edges of an insulated product even when the center of glazing is above the limit for condensation Generally as the insulating value of the glazing is improved the area where condensation can occur is diminished Condensation potential increases as the outdoor temperature is lowered and the indoor relative humidity increases 3 5 2 Condensation Resistance NERC has developed a Condensation Resistance CR value for rating for how well a fenestration product can resist t
287. interlayers in Optics do not have a on them and therefore only interlayers from the LBNL NERC Approved Interlayer list can be used updated by LBNL with every IGDB release and available on the WINDOW Knowledge Base website which means the data for those interlayers was submitted to the IGDB using the criteria specified in Section 1 2 of this document For NFRC verification of the laminate construction submitted by simulators Laminates constructed by simulators in Optics will not have a next to them The simulator shall provide base properties for the complete laminate assembly including solar transmittance solar T visible transmittance photopic T solar reflectance front solar Rf solar reflectance back solar Rb visible reflectance front photopic Rf visible reflectance back photopic Rb Emissivity front EmitF Emissivity back EmitB These values are reported on the Optics screen when the laminate is calculated and also in the WINDOW Detailed Report from the Glazing System Library This requirement is satisfied by submitting a WINDOW mdb database file which includes this laminate An IA or anyone else wanting to check the results can recreate the laminate from the specified layers and verify the calculated values NERC simulators shall assign numbers to the laminates starting with 30 000 The numbers do not have to be unique between simulation laboratories or even between projects in the same labora
288. ion Delete the four reference rectangles Insert the glazing and spacers as usual n Therm File Properties File Properties set the Cross Section Type to Vertical Meeting Rail Assign the Boundary Conditions as follows Interior Frame For the mullion cross section the entire frame width not just half is modeled so all the interior frame boundary condition elements are assigned a Boundary Condition of lt frame type gt Interior Convection Only and a U factor Surface tag of Frame THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 95 8 SPECIAL CASES 8 9 Site Built fenestration products Curtain Walls Window Walls and Sloped Glazing Interior Glazing Set the Boundary Conditions for each glazing system to lt glazing system gt U factor Inside Film and the U factor Surface tag to Edge for the first 63 5 mm 2 5 inches from the sightline and None for the remainder of the glazing system Exterior Frame Set the BoundaryCondition to NFRC 100 2010 Exterior and the U factor Surface tag to SHGC Exterior for the exterior frame Exterior Glazing Set the BoundaryCondition to NFRC 100 2010 Exterior and the U factor Surface tag to None for both exterior glazing systems Mullion Exterior Interior 150 mm 6 0 inches BC lt glazing system gt U factor Inside Film Radiation Model AutoEnclosure U factor tag None BC NFRC 100 2010 Exterior Radiati
289. ion Types eeeeeeeeeeeereereeeee 2 3 29 l Hinged VV ATNGOWS cisiiataccuiasiensquasiaistascaieasuataandad aca tata tna ieaautvonaneuaShens 2 3 DD 25 SHIA WH OWS etrsrisncetecen acces re aech dene seal iapkaueccddea iad aasu dexacanboatianneetes 2 3 2 3 3 Sliding Glass and French Doorsit acsaineuininiuudhwadewndedcns 2 4 24 Trame Wl ALCTIalS sas tay iacicsescuaica van caus Ra E E E E ice dads 2 4 2A As Wood Tramesa a E a 2 4 2A A Era E Saian a a a 2 4 2s VINYL TAES aio E a O 2 5 2 4 4 Fiberglass and Engineered Thermoplastics cece ceseeseeeeeseees 2 5 DAD WOOL COMPOSE edonon a a 2 5 2 4 6 Hybrid and Composite Frames eseeeeseseeseeerrsresresressersrssreeresse 2 5 29 Pasie Glazing Materials sanieren ne RE S E E 2 5 Z9 te ASS so cessnatsodatioi dessa etnaebeia testintna essen cuncdabauebanitestoameisate A 2 6 2 Sa Ne NASTICS aaan a a mesa ushoaiwevibtetuatebeetot ib eudacntinusieeas 2 6 2 0 Improved Ghz Producti hsess tates saciodtanaurirscsatantiasdierssentantonenine nena a 2 7 Zos Tied Glaz rot oss a asc chancel va eta e ica nated aiehauatenuse tact ces 2 7 2 6 2 elective Coatines and FINS tridicdsssiiese bis tockastiot atdastonsyushieetla Sage 2 8 DD POUDIE NE outa asthe aha etait E ni hnctnl ated 2 8 2 6 4 Glass Coatings and Tints in Double Glazing s es 2 8 2 6 5 Gap Width in Multiple Glazed Units eeeeeeeeeeseeeeeeeeeeeeens 2 9 200 Divided By Wits al ec aeperrrererree reer saree tC reerr S 2 9 207 S
290. ion is annoying not only because it clouds the view and stains the interior surfaces but because it may mean that the glazing unit must be replaced if it is a sealed insulating glazing unit In a non sealed unit simpler remedies may correct the situation Factory sealed insulated glazing utilizes a permanent seal to prevent the introduction of moisture The void may be filled with air or dry gases such as argon A desiccant material in the edge spacer between the panes is used to absorb any residual moisture in the unit when it is fabricated or any small amount that might migrate into the unit over many years These windows will fog up when moisture leaking into the air space through the seals overwhelms the ability of the desiccant to absorb it This could happen early in the window s life the first few years if there is a manufacturing defect or many decades later because of diffusion through the sealant Quality control in manufacture sealant selection window design and even installation can influence the rate of failure Once a sealed window unit fails it is not generally possible to fix it and the sealed unit must be replaced Moisture in the unit is also likely to reduce the effectiveness of low E coatings and suggests that gas fills may be leaking out Most manufacturers offer a warranty against sealed glazing failure which varies from a limited period to the lifetime of the window When condensation occurs between glazings in a non sealed
291. iple sill MoGlazing THM Ej Spacer thm Step 2 In the Import dialog box set Format to Therm file Step 3 From the Open dialog select the THERM file s to import into the library Fil o n This same method is used in the WINDOW j Divider Library Files of type Therm files thal mane Open as read only ZA Figure 6 39 Importing THERM files into the WINDOW Frame Library 6 46 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 7 TOTAL PRODUCT CALCULATIONS USING WINDOW 7 1 Overview WINDOW determines the total product U factor according to NFRC 100 and ISO 15099 by calculating an area weighted average of the U factors of the product components and accounting for product height Frame and edge values for each cross section frames and dividers calculated in THERM The U factors are area weighted based on the projected area on a plane parallel to the glass the Projected in the Glass Plane choice in the THERM U factors dialog box not the total surface area of the frame and edge Center of glazing values from WINDOW WINDOW calculates the total product area weighted solar heat gain coefficient SHGC and visible transmittance VT according to the NFRC 200 procedures and the total product Condensation Resistance CR according to the NFRC 500 procedures WINDOW cannot calculate the total product area weighted properties for some fenestration products These include entry doors see Chapter 8 Se
292. issivities in the walls perpendicular to the heat flow direction the program will area weight the emissivity values After the simulation the calculated emissivities can be viewed by double clicking on a frame cavity It is important to remember that the emissivity of a metal surface such as aluminum and steel will depend on the surface finish i e painted or unpainted Many metal cross sections particularly extrusions will be painted on the outside but unpainted on the inside Remember to change emisstances for surfaces based on NFRC 101 that have a different emissivity than the default emissivity for the material All the inner surfaces of these metal extrusions are unpainted so the emissivity of those surfaces shall be changed from the default material emissivity to the correct emissivity for the surface Figure 6 6 Set the emissivity of unpainted metal surfaces such as the inside surfaces of extrusions from the material default based on NFRC 101 to the appropriate emissivity for each surface THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 6 9 6 3 Draw the Cross Sections 6 MODELING FRAME AND EDGE HEAT TRANSFER WITH THERM When the cross section has been simulated double click on a frame cavity to view the resulting heat flow direction temperatures and emissivities automatically calculated by the program as shown in the figure below The information in this dialog box is from a frame cavity in a THERM file
293. ited to an add on panel wm Stack of venetian blind slats Third glazing layer wm with venetian blind Double glazed system Figure 8 143 Head cross section with fully retracted venetian blind between a double glazed system and a third glazing layer THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 158 8 SPECIAL CASES 8 14 Venetian Blinds Between Glass Integral Top of venetian blind assembly Block of Aluminum Alloy used to represent the geometry and material properties of the stack of venetian blind slats in their fully retracted position In this case the stack of blind slats is approximately 15 mm wide and 50 mm long Bottom of venetian blind assembly Dual glazed Third glazing layer system cavity cavity Figure 8 144 The Head cross section with the retracted venetian blind including the stacked slats and the top and bottom assemblies for the blind that are continuous across the section Follow these steps to model a fully retracted venetian blind between a double glazed system and a third glazing layer Note This example was done for Aluminum slat blinds If the material of the blinds is not Aluminum use the appropriate material properties from NFRC 101 Procedure for Determining Thermo Physical Properties of Materials for Use in NFRC Approved Software Programs for the stack of retracted venetian blind slats 1 Draw the Head cross section of the product frame 2 Draw t
294. ith latching mechanisms that compress the sash to the fixed frame and by the addition of compression weatherstripping at the head and sill of double hung windows or the end jamb of horizontal sliders THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 2 3 2 4 Frame Materials 2 FENESTRATION PRODUCTS 2 3 3 Sliding Glass and French Doors As previously noted sliding doors are essentially big sliding windows However they are more complicated because of their size and weight and because the sill is also a door threshold which must keep water out while allowing easy passage of people and objects The threshold is typically the most difficult part of the frame to weatherstrip effectively French doors benefit from being much more like traditional doors than sliding doors French doors can use weatherstripping and operating hardware designed for similar non glazed doors However when there are large openings with multiple hinged doors it is more difficult to positively seal the joints between door leaves and to create the stiffness that will resist infiltration 2 4 Frame Materials The material used to manufacture the frame governs the physical characteristics of the fenestration product such as frame thickness weight and durability but it also has a major impact on the thermal characteristics of the product Increasingly manufacturers are producing hybrid or composite sash and frames in which multiple materials are selected and combined
295. iting Each entry in the Glass Library contains spectral data for that glass layer hence the large database size For any given modeling project only a few of these glass layers are used It is possible to make a much smaller WINDOW6 project database by saving only the records in each library particularly the Glass Library that are used in the defined glazing systems and windows For example saving a project database in this fashion would mean that only the glass layers referenced by the glazing system would be saved in the Glass Library rather than the entire Glass Library that is installed with the program A database with only the referenced glass layers can be less than 1 MB Saving a smaller database in this manner is referred to in this manual as a Project Database meaning it contains only the needed entries for the project being modeled In the List View of each library there is an Export button which can be used to export selected records to another database This Export feature is what can be used to generate a Project Database Many of the libraries reference other libraries for some of their values Therefore when a record is Exported from a library WINDOW also has to export any other records that are referenced from the exported record Figure 7 11 shows how each library is referenced from other libraries The Gas Glass Frame Divider and Environmental Conditions libraries are stand alone libraries meaning they d
296. ived by the surface is reflected while e 0 02 means 98 percent is reflected For uncoated glass e 0 84 which means only 16 percent of the radiant energy received by the surface is reflected A typical pyrolytic coating is a metallic oxide most commonly tin oxide with some additives which is deposited directly onto a glass surface while it is still hot The result is a baked on surface layer that is quite hard and thus very durable which is why this is sometimes referred to as a hard coat A pyrolytic coating can be ten to twenty times thicker than a sputtered coating but is still extremely thin Pyrolytic coatings can be exposed to air cleaned with normal cleaning products and subjected to general wear and tear without losing their Low E properties Because of their greater durability pyrolytic coatings are available on single pane glass and separate storm windows but not on plastics since they require a high temperature process In general though pyrolytic coatings are used in sealed double glazed units with the Low E surface inside the sealed air space While there is considerable variation in the specific properties of these coatings they typically have emittance ratings in the range of e 0 20 to e 0 10 A laminated glass with a spectrally selective Low E sputtered coating on plastic film sandwiched between two layers of glass offers the energy performance of single pane spectrally selective glass and the safety protecti
297. ivider VT dimensionless THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 4 7 4 4 Total Product Calculations 4 SUMMARY OF ALGORITHMS Ad Divider area m ft VTe Edge of glazing VT dimensionless VTe Edge of glazing area m ft VTae Edge of divider VT dimensionless VTae Edge of divider m ft VT Center of glazing VT dimensionless Ac Center of glazing area m ft For opaque components all known frames and dividers the component visible transmittance VT VTa are zero Also note that as defined by NFRC 200 visible transmittance VT VTe VTae For NFRC rating purposes Section 4 7 of NFRC 200 shall be followed to obtain VT values 4 4 4 Condensation Resistance The whole product Condensation Resistance calculation is implemented in WINDOW according to NFRC 500 Procedure for Determining Fenestration Product Condensation Resistance Values The procedure is based on the calculated surface temperature on the indoor side of the glazing and frame boundaries The glazing cavity model for condensation resistance is based on the variable convective surface heat transfer coefficient rather then effective conductivity This is because the spatial distribution of surface temperatures are important and therefore the effective conductivity model for the glazing cavity which produces sufficiently accurate average results does not produce sufficiently accurate local results The details of the methodolog
298. izontal and vertical dimensions of the bounding rectangle which determine the Nusselt number are also shown in this dialog box When there is a constriction in a cavity there will in effect be two separate air flows separated by the constriction This is the logic behind breaking up a cavity at the 5 mm throat constrictions Certain cavities even when there is a constriction in the cavity will already have a small amount of convective heat transfer which results in a Nusselt number close to 1 0 These cavities do not need to be separated into multiple cavities because the constriction is not altering the air flow Note Before a file is calculated the Nusselt number is based on the default temperatures and emissivities for the frame cavity There is a slight chance that the Nusselt number of a frame cavity before a calculation is less than or equal to 1 20 and after the calculation is greater than 1 20 In this case the frame cavity does not need to be broken up Cavity Rectangularization x 9 525 mm Aa t ame Cavity NFRC 100 0 375 aterial e empha a re La Cancel Attributes 9 525 mm Library 0 375 fica at W mK Attributes Horizontal dimension 7 446 mm Double click on the Vertical dimension 7 446 mm frame cavity to display Nu J 1 00 the Properties for Selected Polygons iectionfLet dialog box J mperature 1 0 798 T The Horizontal and Emisswy 00 Vertical dimensions from Si
299. joos EmitF 0 840 E mitE 0 840 Step 1 Select the monolithic layer that you want to add the applied film to and double click on it 12 50 Wavelength microns o Transmission ReHectance Font Refectance back opties ioli File Edit Database wiew Tools Graph Help plela GE Main Database IGDB Glazing System Laminate s H2 Ha Add Glazing Edit Glazing System view All Schematic System Outside Inside gt Layer Filename CLR GlzSys solar T 0 786 0 786 solar Al oor joa zolar Ab jora 0 071 photopic T 0 890 o 890 photopic RF 0 081 0 081 photopic AB 0 081 oos Mi ro RE en Emte psa s40 EET i l 2 i i Hosso fas File Edit Database wiew Tools Graph Help CLR 6 CIG at Float Glass NAS MFRO_2003 ead SDB version 15 0 P Main Database Spectral Properties i z zL Mea Filename CLR 6 C1G Step 2 ote The selected layer will appear in the 1 column of the Glazing System solar T 0 786 solar Af 0 071 Glazing System Laminate i j Hz H3 Sytem i solar Ab 0 071 vn t 3 S ep o 0 890 photopic T 0 60 solar T 0 786 Cc oo am Click on the 1 column wher photopic Ff o 081 Edit Database view Tools photopic Ab 0 081 EREE the substrate was added solar RI iia E mitF 0 840 Flip Layer o solar Ab a07 Emit 0 840 photopic T 0 890 Change Thickness 12 50
300. l June 2013 8 14 8 SPECIAL CASES 8 3 Dividers 6 Define the boundary conditions using the AutoEnclosure choice for the Radiation Model BC Adiabatic U factor tag None a BC lt glazing system gt U factor Inside Film Radiation Model AutoEnclosure U factor taa None BC NFRC 100 2010 Exterior U factor tag None BC lt glazing system gt U factor Inside Film Radiation Model AutoEnclosure U factor tag Edge BC lt glazing system gt U factor Inside Film Radiation Model AutoEnclosure U factor tag Frame BC NFRC 100 2010 Exterior U factor tag SHGC Exterior BC lt glazing system gt U factor Inside Film Radiation Model AutoEnclosure U factor tag Edge BC NFRC 100 2010 Exterior U factor tag None BC lt glazing system gt U factor Inside Film Radiation Model AutoEnclosure U factor tag None BC Adiabatic U factor tag None Figure 8 16 Assign the boundary conditions THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 15 8 SPECIAL CASES 8 3 Dividers 7 Calculate the results THERM 6 3 DividerContoured 16mm THM E x da File Edit View Draw Libraries Options Calculation Window Help amp x D Waal amp 4 Oo g e ragya F e u e Step 1 Click on the Calc toolbar button to start the simulation L a Step 3 Click on the Calculation Show U factors menu choice to see the U factor results Step 2 When the simulation is finishe
301. lation Manual June 2013 8 12 8 SPECIAL CASES 8 3 Dividers 4 Draw or copy and paste from another THERM file the polygons in the cavity that represent the divider The figure below shows the divider for this example drawn with the material set to Aluminum Alloy Draw the divider in the cavity between the two glazing systems Figure 8 14 Draw the polygons to represent the divider THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 13 8 SPECIAL CASES 8 3 Dividers 5 Fill the cavities between the divider and the glass layers and inside the divider with the material Frame Cavity NFRC 100 Because internal dividers are only modeled if the gap between the edge of the divider and the glass surface is less than 3 mm the 5 mm rule for linking glazing cavities and frame cavities is not applied to internal dividers the cavity surrounding the divider is modeled as a frame cavity with boundaries at the upper and lower edges of the divider Check the emissivity values for the inside surface by double clicking on the surface of the extruded metal divider If there is a different surface finish on each side of the material change the default material emissivity as appropriate based on the NFRC 101 values Frame Cavity Surface X Emissivity 0 200 A MIN Cancel A E 14 17 4 4 Figure 8 15 Fill the divider frame cavities with Frame Cavity NFRC 100 THERM6 3 WINDOW6 3 NFRC Simulation Manua
302. lation clips and spacers at the bolts Site built modeling is partially dependent on the installation of the product Make sure that the drawings you have show the installation Site built products are typically multiple lite systems where the intermediate vertical and horizontal frame members repeat in some pattern Curtain Walls per NFRC 100 Table 4 3 shall be simulated and tested with the intermediate verticals as jambs and intermediate horizontals as the head and sill members Window Walls or also known as strip windows per NFRC 100 Table 4 3 shall be tested and simulated with intermediate verticals as jambs and standard head and sill members Sloped Glazing may also be rated based on the centerline dimensions if utilized like a curtain wall or window wall except for solariums and sunrooms Sloped glazing of solariums and sunrooms shall be simulated and tested with standard jamb head and sill members Modeling of the representative products above used to compare to the physical validation test is as follows 1 Simulate the full vertical intermediate member twice for the left and right jambs a Once with the left glass replaced with wood which is the same thickness as the IG unit b Once with the right glass replaced with wood which is the same thickness as the IG unit The wood shall extend to the original sightline 2 Simulate the horizontal members a If this is for a curtain wall then once with the top gla
303. lear acrylic except that it diffuses light and obscures the view It comes in varying degrees of light transmittance Most bubble skylights are made of frosted acrylic Clear polycarbonate is like acrylic sheet but it is harder and tougher offering greater resistance to scratching and breakage It is more expensive than acrylic Fiber reinforced plastic is a tough translucent flexible sheet material with good light diffusing properties Short lengths of fiberglass are embedded in a polymer matrix to form flat or ribbed sheets Stiff insulating translucent panels are created by bonding double layers to a metal frame and adding fiberglass insulation It is also formed into corrugated sheets as a translucent roofing material Surface erosion may shorten its useful life Extruded multicell sheet usually made with acrylic or polycarbonate plastic is a transparent or tinted plastic extruded into a double or triple wall sheet with divider webs for stiffness insulating value and light diffusion Polyester is a thin film used to carry specialized coatings and or to divide the air space between two layers of glass into multiple air spaces Highly transparent it is protected from abuse and weathering by 2 6 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 2 FENESTRATION PRODUCTS 2 6 Improved Glazing Products the two exterior glass layers It can also be used in tinted or coated forms as film that is glued to the inner surface of exis
304. lengths in the solar spectrum while blocking the lower energy radiant heat in the far infrared range that is an important heat loss component These are the strategies of spectrally selective and low emittance coatings described later in the chapter 80 transmitted Dh reflected 6 absorbed Oh absorbed and convected and reradiated away into Space Clear glass HO transmitted 26h reflected 18 absorbed 6 absorbed and convected and reradiated away into space Reflecting glass 40 transmitted 5 reflected 45h absorbed 12 absorbed and convected and reradiated away into space Heat absorbing glass Figure 3 5 Different glass types have different characteristics for the amount of solar radiation reflected transmitted absorbed and re radiated 3 7 2 Reflectance Just as some light reflects off of the surface of water some light will always be reflected at every glass surface A specular reflection from a smooth glass surface is a mirror like reflection similar to when you see an image of yourself in a store window The natural reflectivity of glass is dependent on the quality of the glass surface the presence of coatings and the angle of incidence of the light Today virtually all glass manufactured in the 3 12 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 3 FENESTRATION HEAT TRANSFER BASICS 3 8 Infrared Properties of Glazing Materials Emittance United States is float glass and has a very si
305. lete Height 1500 mm Save Area 1800 m2 Cancel Find fib 7 records found Report i 90 af Name Source Type Uvalue Edge Edge Glazing Environmental Conditions Uvalue Correlation Thickness V Dividers NFRC 100 2010 X Wim2 K Wm2 K mm Dividers Alum Divided ASHRAE N A NAA N A Class N A Butyl Divided ASHRAE N A NAA N A Class2 N A Displ de a es Wood Divided ASHRAE Suspende N A N A Class3 N A Total Window Results Insul Divided ASHRAE Suspende N A NZA Class4 N A Click on a component to display characteristics below U factor 1 9350 W m2 K Alum Suspended ASHRAE Suspende N A NA Class5 NA suac 05263 Da Vinyl Suspended ASHRAE N A N A N A Classi N A al ESE Detail Name divider 3mm THM gt TT qem ID Uedge 1 732 W m2 K CR 43 Detail Source 2 Edge area 0 721 m2 Ufactor 2 010 W m2 K PFD 25 4 Area 0 213 m2 Abs 0 300 Normal v 4 For Help press F1 Mode NFRC SI Figure 7 10 Window Library List View for the U factor with Dividers case 7 12 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 7 TOTAL PRODUCT CALCULATIONS USING WINDOW 7 5 Project Databases 7 5 Project Databases WINDOW 6 databases can be quite large For example the default database w6 mdb that is included in the program installation package is approximately 27 MB One of the main reasons for the large size is the records in the Glass Library there are 3500 records in that library as of this wr
306. level is a contributing factor reducing interior humidity is an important component of controlling condensation Condensation can also be a problem on the interior surfaces of window frames Metal frames in particular conduct heat very quickly and will sweat or frost up in cool weather Solving this condensation problem was a major motivation for the development of thermal breaks for aluminum windows Infiltration effects can also combine with condensation to create problems If a path exists for warm moisture laden air to move through or around the window frames the moisture will condense wherever it hits its dew point temperature often inside the building wall This condensation can contribute to the growth of mold in frames or wall cavities causing health problems for some people and it encourages the rotting or rusting of window frames Frames must be properly sealed within the wall opening to prevent this potential problem In some instances the infiltration air will be dry such as on cold winter days and it will thus help eliminate condensation on the window surfaces Condensation can cause problems in skylights and roof windows as well as typical windows Leaky skylights are frequently misdiagnosed What are perceived to be drops of water from a leak are more often drops of water condensing on the cold skylight surfaces A skylight is usually the first place condensation will occur indicating too much moisture in the interio
307. licking on a boundary condition which has the standard boundary conditions defined by NFRC shown in Table 6 4 as well as Adiabatic By default the exterior boundary conditions are blue interior boundary conditions are red and the adiabatic boundary condition is black Table 6 4 Boundary condition definitions Radiation Convective Film Coefficient Boundary Condition Model Tilt 90 Tilt 20 NERC 10 2010 terior Blackbody se s o Interior Aluminum Frame Automatic 3 29 0 579 4 65 0 819 Enclosure Model convection only Interior Thermally Broken Automatic 0 528 Enclosure Model Frame convection only Interior Thermally Automatic 0 549 0 761 Enclosure Model Improved Frame convection only Interior Wood Vinyl Frame Automa 0 429 0 544 Enclosure Model convection only WINDOW T System Automatic Depends on the WINDOW calculations for the imported boundary condition Enclosure Model glazing system lt filename gt lt glazing system name gt U factor Inside Film 6 30 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 6 MODELING FRAME AND EDGE HEAT TRANSFER WITH THERM 6 5 Defining Boundary Conditions BC Adiabatic U factor surface tag None BC NFRC 100 2010 Exterior U factor surface tag None BC lt glazing system name gt U factor Inside Film U factor surface tag None BC lt glazing system name gt U factor Inside Film U factor surface tag Edge E BC Interior Aluminum Frame convecti
308. light 3mm Generic Mode NFRC New Type Skylight v gt gt coy ly Width 1200 mm __Delete Height 1200 mm Save Area 1 440 m2 Report Tit 20 Environmental Conditions Dividers NFRC 100 2010 sa Dividers Display mode Normal v Total Window Results U factor 3 5062 Wme2 K Click on a component to display characteristics below Frame SHGC 0 6623 Detail Name SL THM gt gt YT 0 7017 ID 3 Uedge 3 553 W m2 K CR 36 Detail Source 2 Edge area 0 067 m2 Ufactor 4 760 W m2 K PFD 43 0 Area 0 050 m2 Abs 0 300 Figure 8 71 Create the whole skylight in the Window Library 8 5 4 Domed Skylights Glass Block The following describes the steps for simulating a domed skylight or glass block product to obtain the total product U factor THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 69 8 SPECIAL CASES 8 5 Skylights 1 Determine the glazing components conductance Cs per ASTM C1363 2 Calculate the effective conductivity to 3 significant figures in Btu h ft F by the following formula Keffglass Cs t712 Where Cs Conductance of glass as determined per ASTM C1363 test T thickness of sample in inches 12 conversion factor from conductance to conductivity Btu in hr ft2 2F to Btu h ft 2F 3 Make anew a glass layer in the Glass Library and set the conductance to the calculated Keffglass value a Enter the thickness of the sample b Ifthe sample is
309. lind section BC Adiabatic U factor Tag None BC Interior lt frame type gt Convection only Radiation Model AutoEnclosure U factor Tag Frame BC lt glazing system name gt U factor Inside Film Radiation Model AutoEnclosure U factor Tag Frame BC lt glazing system name gt U factor Inside Film Radiation Model AutoEnclosure U factor Tag Edge THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 187 8 SPECIAL CASES 8 14 Venetian Blinds Between Glass Integral BC Adiabatic U factor Tag None BC lt glazing system name gt U factor Inside Film Radiation Model AutoEnclosure U factor Tag None BC NFRC 100 2001 Exterior U factor Tag None BC lt glazing system name gt U factor Inside Film Radiation Model AutoEnclosure U factor Tag Edge BC lt glazing system name gt U factor Inside Film Radiation Model AutoEnclosure U factor Tag Frame BC Interior lt frame type gt Convection only Radiation Model AutoEnclosure U factor Tag Frame BC NFRC 100 2001 Exterior U factor Tag SHGC Exterior to BC Adiabatic U factor Tag None Figure 8 175 Define the boundary conditions for Sill Non Retractable Closed Venetian Blind section THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 188 8 SPECIAL CASES 8 14 Venetian Blinds Between Glass Integral BC Adiabatic U factor Tag None BC lt glazing system name gt U factor Ins
310. ll be independent of the temperature driven heat transfer Absorbed solar radiation will partially be transmitted into the conditioned space and will be included in SHGC These three modes of heat transfer are shown schematically in Figure 3 1 Heat flows from warmer to cooler bodies thus from inside to outside in winter and reverses direction in summer during periods when the outside temperature is greater than indoors The amount of heat transfer due to these three processes is quantified by its U factor W m C or Btu h ft F The inverse of heat flow or resistance to heat transfer is expressed as an R value NFRC s rating system quantifies and predicts U factors Double glaze window OUTDOORS INDOORS Convection and conduction gt A n a Thermal Figure 3 1 Mechanisms of heat transfer in a fenestration product 3 2 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 3 FENESTRATION HEAT TRANSFER BASICS 3 3 Temperature Driven Heat Transfer 3 3 1 Conduction Compared to a well insulated wall heat transfer through a typical older fenestration product is generally much higher A single glazed fenestration product has roughly the same insulating qualities as a sheet of metal most of the insulating value comes from the air layer on each surface of the glass Such a product can be considered a thermal hole in a wall and typically has a heat loss rate ten to twenty times that of the wall A product with s
311. lp DSH SB Sli M n Baemi OEZ Divider Library C Program FilesS LEN LYW NO OW Bas Dividers mdb Detailed view Edge E dge Glazing Uwale Correlation Thickness Werne B wW me k mm mm Mame Uvalue Ffd Abs Color Butyl Divided ASHRAE N A HA N A Class MA 159 090 2 3 Wood Divided ASHARAE Suspende M A hlii Cla a 4 InsulDivided ASHRAE Suspende 5 Alum Suspended ASHAAE Suspendi 6 Vinyl Suspended ASHRBAE Matty 7 DividerContoured THM Therm Yertical D a DividerContouedGasFilled THI Therm Vertical D A TrueDividedLite THM Step 1 From the WINDOW Frame Library click on the Import button An open window will open Select the THERM file Pint al or files to import File name SimulatedDividedLite THM For Help press Fl Files of type Therrn files thm F Cancel Step 2 Specify the record number or use Open as read only the program default number which is an increment from the last record gt p x Divider Library C P Files LBNL WINDOW63 e E Program 0K j 0 x bila ANE OOTA FiestCENL THERMENDvider SimustedDivided L__OS File Edit Libraries Record Tools wiew Help DSH e 2ile Cancel EENE SE S E ID for new record fa r Divider Library C Program Files4 LBNLAWINDOW ES Detailed View Update Dvermrite existing records Hame Souri Color New Saree Ha cena Copy
312. m clear is what the applied film manufacturers submit to the IGDB and will be in that database The other two cases Single 6 mm clear and Single 6 mm gray can now be calculated with Optics 8 12 4 Creating a Layer with an Applied Film in Optics 8 12 4 1 Adding an Applied Film to an Uncoated Layer You can apply a film to a monolithic layer in Optics to create a new applied film layer To apply a film to a monolithic layer follow the steps below THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 133 8 SPECIAL CASES 8 12 Creating an Applied Film Layer in Optics for NFRC Certification Click on the Glazing System tab Add the desired layer to a layer column under the Glazing System tab Select the monolithic layer by clicking on the desired layer number button Add an Applied Film to the selected glazing layer in one of the following ways Choose the menu option Edit Change Add Film Edit Delete Layer Flip Layer Change Thickness Change Substrate 4dd Coating Figure 8 123 Select a monolithic glass layer click on the Layer button and select the Edit Add Film menu choice OR Right click on the selected glazing layer button and select the choice Add Film The Change Glazing dialog box will appear The film name box is highlighted in blue click on it to select an applied film from the database you must select an Applied Film layer not a Film layer You must choose a film that i
313. m the choices in Table 6 4 found in the THERM Boundary Condition Library The technique for doing this is described in detail in Chapter 6 Defining Boundary Conditions of the THERM User s Manual In THERM in addition to assigning boundary conditions to a boundary segment the U factor Surface Tags must also be assigned for each boundary condition The U factor Surface Tags which are selected from the U factor Names library are used by THERM to calculate the component U factors For a THERM U factor calculation that will be used in WINDOW it is necessary to use the following U factor Surface Tags with the same capitalization WINDOW will not recognize any other values Frame Use this tag for all interior boundary conditions that are part of the frame U factor calculation including the boundaries of the glazing system below the sight line See NFRC 100 Figure 2 Fenestration Product Schematic Vertical Section THERM will automatically assign the U factor tag of Frame to the portion of the glazing system that is below the sight line based on the Site Line to Bottom of Glass value entered when the glazing system is inserted from WINDOW Edge Use this tag for all interior boundary conditions that are to be used in the edge of glazing calculation THERM will automatically assign the U factor tag of Edge based on the dimension entered in the Edge of Glass Dimension when importing the glazing system which for NFRC modeling should be 6
314. mdb Detailed View Pale Copy Delete Krypton enor Air 52 Argon S522 Mis Aur 122 Argon 224 Krypton 6622 Mis Air 5 7 krypton 9522 Mis Air 10 7 Argon 50 Mis Advanced o records found Import Export Report Print For Help press Fl mo Oo w Oo Fe to fo 4 gt n Balei oF Conductivity 0 024069 0 016349 0 008664 0 005160 0 016704 0 011450 0 009191 0 017063 K Viscosity kgm 0 000021 0 000023 0 000021 0 000021 0 000023 0 000023 0 000021 Cp J kg k 1006 10327 521 929016 248 091003 156 339996 539 729614 J22 703613 261 636536 558 0331 42 Density kins 1 761832 af af fob 5 056475 1 767349 3 014005 3 615515 1 732865 El Mode NFRC si NUM 5CRL 5 x Prandtl Figure 8 19 Make the necessary gas mixture in the WINDOW Gas Library THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 18 8 SPECIAL CASES 8 3 Dividers 2 Import the WINDOW gas mixture into the THERM Gas Library if it is not already there THERM 6 3 Untitled 1 i l0 x fa File Edit View Draw Libraries Options Calculation Window Help 7 G x Deh a E l Set Material F4 B 7 Eul Set Boundary Condition FS Material Library ShiFt F4 Boundary Condition Library Shift FS Step 1 Click as Library ShiFk F Gas Librar on the Gas Library from Select Material Boundary Gondition MO kee ls j Step 2 Click on
315. me type gt Frame convection only Radiation Model AutoEnclosure l U factor tag Frame BC NFRC 100 2010 Exterior U factor tag SGHC Exterior BC Adiabatic U factor tag None Figure 8 69 Boundary condition and U factor tag settings for skylight jamb example THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 68 8 SPECIAL CASES 8 5 Skylights In WINDOW Calculate the Total Product U factor 1 Inthe WINDOW Frame Library import the THERM files for the Head Sill Jamb and any other needed cross sections that were modeled Frame Library C SUsers Public LBNL YAN DOW ESS kulight mdb Detailed View Update Frame Edge Edge Glazing ID source Type Uvalue Uvalue Correlation Thickness Pid Wi ma B Wilm2 K mm mm 1 HD THM Therm Head 4 795 3553 N A 169 430 Copy 2 JB THM Therm Sill 4 fed 3 551 Ay 16 9 43 0 Delete 3 SL THM Therm Sill 4 760 3551 N A 16 93 43 0 Find Jamb has cross section type Sill see fC Jamb description above Advanced 3 records found Import Export Report Print Figure 8 70 Import the skylight THERM files into the WINDOW Frame Library 2 Construct the whole skylight in the WINDOW Window Library by using the THERM files for the frame components and the glazing system for the center of glass Make sure that Type Skylight and Tilt 20 File Edit Libraries Record Tools View Help bege E Kk rj Bae lli o Z kK e Kw List ID 1 Calc F9 Name Sky
316. metry make sure to reference the same material record in the Shade Material Library e Effective Openness Fraction If a Shading Layer is imported from the CGDB this value will automatically be set If you are making a new record the Effective Openness Fraction 0 for the Closed blind case e Slat Width appropriate value in this example 14 8 mm e Spacing spacing between each slat in this example 12 mm THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 179 8 SPECIAL CASES e Tilt closed 90 or closed 90 depending on the product geometry Aan a hat gaa slat thickness if fo Tai m r My spacing ay ki eR Ti E tilt angle f blind thickness Figure 8 166 Venetian blind geometry definition 8 14 Venetian Blinds Between Glass Integral e Blind thickness This value is not editable and shows the width of the blind assembly based on the slat tilt In this Closed case the blind thickness is very small e Rise this value defines the curve of the slat and is defined in the CGDB for each Venetian blind product It can be changed if it does not represent the slat curvature being modeled this would be necessary if the slat width was changed for example Shade Material Library When a Shading Layer record is imported from the CGDB the Shad e Material is automatically imported and therefore in general it is not necessary to add or change records in the Shade Mat
317. milar quality with respect to reflectance The sharper the angle at which the light strikes however the more the light is reflected rather than transmitted or absorbed Even clear glass reflects 50 percent or more of the light striking it at incident angles greater than about 70 degrees The incident angle is formed with respect to a line perpendicular to the glass surface Coatings can often be detected by careful examination of a reflected bright image even if the coating is a transparent low E coating Hold a match several inches from a fenestration product at night and observe the reflections of the match in the glass You will see two closely spaced images for each layer of glass since the match reflects off the front and back surface of each layer of glass A wider spacing between the two sets of pairs of images occurs with a wider air space between the glass panes A subtle color shift in one of the reflected images normally indicates the presence of a low E coating The reflectivity of various glass types becomes especially apparent during low light conditions The surface on the brighter side acts like a mirror because the amount of light passing through the fenestration product from the darker side is less than the amount of light being reflected from the lighter side This effect can be noticed from the outside during the day and from the inside during the night For special applications when these surface reflections are undesirable i e
318. mm Check the Use CR Model for Window Glazing Systems if appropriate wf E Mmm z Step 4 Enter the appropriate Gap Properties For most NFRC simulations Default which uses the values directly from WINDOW is the correct settina Step 5 Define the Boundary Conditions Click on Use U factor values Exterior Boundary Conditions Set to Use existing BC from Library and set the value to NFRC 100 2010 Exterior Interior Boundary Condition Set to Use convection plus enclosure radiation which sets the boundary condition by default to AutoEnclosure Figure 6 16 Inserting a Glazing System into a cross section THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 6 4 Importing Glazing Systems 6 MODELING FRAME AND EDGE HEAT TRANSFER WITH THERM The NFRC modeling requirements when inserting a glazing system are CR cavity height See table 6 2 Section 6 4 5 for values Only used if the Condensation Resistance model is activated Edge of Glass 63 5 mm 2 5 inches Glazing System Height 150 mm 6 0 inches for all products Exterior Boundary Condition Set to Use existing BC from library and select NFRC 100 2010 Exterior This will be applied automatically by the program on the exterior surfaces of the glazing system and frame Interior Boundary Condition Set to Use convection plus enclosure radiation This will cause the program to automatically
319. n WINDOW to calculate the overall product U factor THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 9 3 9 2 Problem 1 Vinyl Fixed Window 9 SAMPLE PROBLEMS 9 2 4 Edge of glazing and Frame Modeling for U Factor THERM Because this is a fixed window where the head sill and jambs have the same geometry the frame and stop portions of the cross sections created in THERM will be the same However due to the ISO 15099 modeling assumptions for gravity vectors and Condensation Resistance modeling it is necessary to create a unique cross section for each component type to reflect the proper orientation of the glazing system and gravity vector The table below shows the files that are associated with this example Table 9 2 Files associated with the vinyl window example Cross Section DXF Filename THERM Filename Sill Vinyl Frame dxf Vinyl Sill thm Head Vinyl Frame dxf Vinyl Head thm Jamb Vinyl Frame dxf Vinyl Jamb thm The table below shows the resulting U factors for the vinyl frame and divider cross sections Table 9 3 THERM results for the vinyl window cross sections ee Frame U Factor Edge U Factor Cross Section Btu hr ft F Btu hr ft F Head 1 6037 0 2824 2 1151 0 3725 Jamb 1 6498 0 3182 2 1176 0 3706 Divider 2 6050 0 4593 1 9986 0 3521 Figures 9 2 through 9 5 show the THERM cross sections and U factor results for this window 9 4 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 9 SAMPLE PROBLEMS 9 2
320. n blind panels e Apply the 5 mm rule to the throat of the cavity next to the glazing system cavity If it is less than 5 mm make it into a frame cavity e Ifa cavity touches two glazing systems and the throat at each glazing system is gt 5 mm link to the glazing system with the highest Keff double click on the glazing sytem to see the Keff value for each gap Sealed glazing units IGs e The 5mm rule is not applied to sealed IG units all the cavities that touch the glazing cavity such as U shaped spacer cavities are linked even if the throat is less than 5 mm Internal Dividers Grills e These rules do not apply to internal dividers which are only modeled if the distance between the edge of the internal divider and the glass layer is lt 3 mm See Section 8 3 Dividers THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 6 21 6 4 Importing Glazing Systems 6 MODELING FRAME AND EDGE HEAT TRANSFER WITH THERM This portion of the THERM model This portion of the THERM model represents an unsealed unit storm represents a sealed IG unit Therefore panel Therefore the 5 mm rule for the 5 mm rule for linking cavities is linking cavities is used NOT applied and all the cavities around the spacer that touch the The throats of the circled cavities are glazing cavity are linked to that glazing lt 5 mm so they are modeled as cavity Frame Cavity NFRC 100 and not linked to the glazing system cavity
321. n off by very hot objects the far infrared given off by warm room temperature objects and the longer microwaves and radio waves Glazing types vary in their transparency to different parts of the spectrum On the simplest level a glass that appears to be tinted green as you look through it toward the outside will transmit more sunlight from the ereen portion of the visible spectrum and reflect absorb more of the other colors Similarly a bronze tinted glass will absorb the blues and greens and transmit the warmer colors Neutral gray tints absorb most colors equally This same principle applies outside the visible spectrum Most glass is partially transparent to at least some ultraviolet radiation while plastics are commonly more opaque to ultraviolet Glass is opaque to far infrared radiation but generally transparent to near infrared Strategic utilization of these variations has made for some very useful glazing products The basic properties of glazing that affect solar energy transfer are Visible transmittance Reflectance Absorptance Each is described below 3 10 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 3 FENESTRATION HEAT TRANSFER BASICS 3 7 Solar Properties of Glazing Materials 3 7 1 Transmittance Transmittance refers to the percentage of radiation that can pass through glazing Transmittance can be defined for different types of light or energy e g visible light transmittance UV transmitta
322. nce or total solar energy transmittance Each describes a different characteristic of the glazing Visible transmittance is the total fenestration product system s transmittance across the visible portion of the solar spectrum Although VT can be determined for any angle of incidence the default and most commonly used reference is normal incidence solar radiation Transmission of visible light determines the effectiveness of a type of glass in providing daylight and a clear view through the fenestration product For example tinted glass has a lower visible light transmittance than clear glass With the recent advances in glazing technology manufacturers can control how glazing materials behave in these different areas of the spectrum The basic properties of the substrate material glass or plastic can be altered and coatings can be added to the surfaces of the substrates For example a product optimized for daylighting and for reducing heat gains should transmit an adequate amount of light in the visible portion of the spectrum while excluding unnecessary heat gain from the near infrared part of the electromagnetic spectrum THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 3 11 3 7 Solar Properties of Glazing Materials 3 FENESTRATION HEAT TRANSFER BASICS On the other hand a product optimized for collecting solar heat gain in winter should transmit the maximum amount of visible light as well as the heat from the near infrared wave
323. nce of glass is increased by adding to the glass chemicals that absorb solar energy If they absorb visible light the glass appears dark If they absorb ultraviolet radiation or near infrared there will be little or no change in visual appearance Clear glass absorbs very little visible light while dark tinted glass absorbs a considerable amount The absorbed energy is converted into heat warming the glass Thus when these heat absorbing glasses are in the sun they feel much hotter to the touch than clear glass They are generally gray bronze or blue green and are used primarily to lower the solar heat gain coefficient and to control glare Since they block some of the sun s energy they reduce the cooling load placed on the building and its air conditioning equipment Absorption is not the most efficient way to reduce cooling loads as discussed later 3 8 Infrared Properties of Glazing Materials Emittance When heat or light energy is absorbed by glass it is either convected away by moving air or reradiated by the glass surface This ability of a material to radiate energy is called its emissivity Fenestration products along with all other household objects typically emit or radiate heat in the form of long wave far infrared energy This emission of radiant heat is one of the important heat transfer pathways for a fenestration product Thus reducing the product s emission of heat can greatly improve its insulating properties T
324. ncident total irradiance W m Btu h ft This equation shows that the properties of U factor SHGC and infiltration are major factors which determine the energy flow through a fenestration product For this reason the NFRC rating system rates the U factor THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 3 1 3 3 Temperature Driven Heat Transfer 3 FENESTRATION HEAT TRANSFER BASICS SHGC and air infiltration of products and the NFRC 100 NFRC 200 and NFRC 400 documents define the procedures for calculating these values for the total product 3 3 Temperature Driven Heat Transfer Fenestration product heat loss gain due to temperature is a combination of three modes of heat transfer 1 Conduction heat traveling through a solid material the way a frying pan warms up through glazing spacer and frame elements 2 Convection the transfer of heat by the movement of gases or liquids like warm air rising from a candle flame through air layers on the exterior and interior fenestration product surfaces and between glazing layers 3 Radiative heat transfer the movement of heat energy through space without relying on conduction through the air or by movement of the air the way you feel the heat of a fire between glazing layers or between IG units and interior or exterior spaces Solar radiation absorbed by glazing layers will contribute to the temperature driven heat transfer while solar radiation transmitted by the glazing system wi
325. nction in THERM but the underlay can be used to trace the cross sections see Chapter 5 Drawing Cross Section Geometry in the THERM User s Manual 9 18 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 9 SAMPLE PROBLEMS 9 3 Problem 2 Aluminum Horizontal Slider Window Table 9 11 shows the resulting U factors for the vinyl frame and divider cross sections Table 9 11 THERM results for the vinyl window cross sections OO Fever eeur O Cross Section Btu hr ft F Jamb Vent 5 3240 0 9376 2 1173 0 3729 Jamb Fixed 8 0264 1 4135 2 0708 0 3647 Meeting Rail 7 0598 1 2433 2 0251 0 3566 The figures on the following pages show THERM file cross sections and U factor results for this window Head Fixed 7 1510 1 2594 2 0810 0 3665 THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 9 19 9 3 Problem 2 Aluminum Horizontal Slider Window 9 SAMPLE PROBLEMS Sill Vent BC Adiabatic Cross Section Type Sill peeled ane Gravity Vector Down BC 3 mm CIG U factor Inside Film Radiation Model AutoEnclosure U factor tag None BC NFRC 100 2010 Exterior Radiation Model Blackbody U factor tag None BC 3 mm CIG U factor Inside Film Radiation Model AutoEnclosure U factor tag Edge BC NFRC 100 2010 Exterior Radiation Model Blackbody U factor tag SHGC Exteri actor tag MSTIOL BC Interior Thermally Broken Frame convection only Radiation Model AutoEnclosure U factor tag Frame t BC
326. nd have the same name as the glazing system cavity e The linked cavity will turn gray Apply the 5 mm rule to this space model this space as a frame cavity rather than connecting it to the glazing system cavity it is 1 75 mm in this example Libraries Options Calculation Window Help The width of this cavity is ae ater iy lt 5 mm so it is not linked Set Boundary Condition FS to the glazing system Material Library Shift F4 cavity Boundary Condition Library Shift FS Gas Library Shift F Select Material Boundary Condition Glazing Systems F UFactor Mames Create Link Remove Link The width of this cavity is gt 5 mm so it is not linked to the glazing system cavity and is modeled as a frame cavity PRS The width of this cavity is gt 5 mm so it is linked to the glazing system cavity This frame cavity starts where the throat is 5 mm and then is modeled as a frame cavity Figure 8 141 Fill the cavity next to the venetian blind by linking it to the main glazing cavity THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 155 8 SPECIAL CASES 8 14 Venetian Blinds Between Glass Integral 5 Generate the Boundary Conditions The section of the warm side of the glazing system adjacent to the retracted venetian blind should be defined with a U factor Surface tag of Frame BC Interior lt frame type gt Convection only Radiation Model AutoEnclosure U factor
327. nditions Exterior Boundary Condition Use existing BC from library select NFRC 100 2001 Exterior and assign the SHGC Exterior U factor tag to the exterior frame components Interior Boundary Condition Use convection plus enclosure radiation for Glazing System use appropriate convection only frame boundary condition for the frame components Simulate each model In WINDOW Import the THERM frame profiles that have the correct geometry for the glazing systems into the Frame Library In the Window Library create the window referencing the matching frames and glazing systems including the meeting rail you cannot match the glazing system thicknesses in the meeting rail so just reference it Calculate the overall product values from this combination of components Close the program open the W6 ini file and do the following Delete the line FrameToleranceGlazingSystemThickness 5 THERM6 3 WINDOWG6 3 NFRC Simulation Manual June 2013 8 46 8 SPECIAL CASES 8 4 Storm Windows Or yy Puta semicolon in front of it which keeps it in the file but makes it a comment instead of a command This way it will be there the next time you need to use it FrameToleranceGlazingSystemThickness 5 THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 47 8 SPECIAL CASES 8 4 Storm Windows 8 4 2 Storm Window Example The following example problem based on the product in Figure 8 46 is explained
328. nductivities of the materials that the thermal bridging material replaces Conductivities of materials can be obtained from the THERM Material Library Conductivities of air filled cavities such as frame cavities are assumed to be 0 024 W m K or 0 014 Btu hr ft F Using a cross section that contains the non thermal bridging material measure the depths of each element of the non thermal bridging material that will have a different thermal conductivity in the non bridging cross section Use the conductivities of the non thermal bridging materials and depths of the non thermal bridging materials in Equation 2 below to determine the Resistance R for each non thermal bridging element Sum the resistances Rt and divide by the total depth of the non thermal bridging elements to obtain Kn as shown in Equation 3 to calculate the conductivity of the non thermal bridging elements Calculate the fraction of thermal and non thermal bridging material along the length of the facade using Equations 4 and 5 Calculate the final effective conductivity value for the thermal bridging elements using Equation 1 In THERM define a new material with the Keff value derived in Step 7 and assign it to the cross section polygons that represent the thermal bridging elements Simulate the model THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 78 8 SPECIAL CASES 8 8 Non Continuous Thermal Bridge Elements 8 8 4 Equations Calculate the eff
329. ne Gravity eckor e4 m Modeling Assumptions Cross Section Sill Gravity Arrow Down BC Interior Wood Vinyl Frame convection only Radiation Model AutoEnclosure BC NFRC 100 2010 Exterior U Factor Surface tag Panel Core Radiation Model Blackbody U Factor Surface tag SHGC Exterior fo BC Adiabatic U Factor Surface tag None x U factor delta T Length Wen K E mm Rotation Panel Core 2 5843 39 0 63 5 NA Projected Y SHGC Exterior 2 5843 39 0 63 5 Nea Projected Ki Z Eror Energy Horm 0 00 Export Figure 9 50 THERM cross section and U factor results for the panel core cross section THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 9 57 9 5 Problem 4 Door 9 SAMPLE PROBLEMS Door Lite Sill BC Adiabatic U Factor Surface tag None TE o BC 3 mm Clear Air Clear U factor Inside Film Radiation Model AutoEnclosure U Factor Surface tag None Modeling Assumptions Cross Section Sill Gravity Arrow Down BC 3 mm Clear Air Clear U BC NFRC 100 2010 Exterior factor Inside Film Radiation Model Blackbody Radiation Model AutoEnclosure U Factor Surface tag None U Factor Surface tag Edge A BC NFRC 100 2010 Exterior Radiation Model Blackbody U Factor Surface tag SHGC Exterior BC Interior Wood Vinyl Frame convection only Radiation Model AutoEnclosure U Factor Surface tag Frame BC Adiabat
330. ne 2013 8 91 8 SPECIAL CASES 8 9 Site Built fenestration products Curtain Walls Window Walls and Sloped Glazing 8 9 2 Curtain Wall Modeling Procedure Modeled as Head but height Modeled as 2 helg Intermediate horizontal Mullion full width frames Modeled as Jamb but width Modeled as Jamb Modeled as Sill pela but 72 width but height Figure 8 88 Curtain wall simulation model represented by dotted lines for rating where the framing members are modeled at half their width Modeled as Head Modeled as full height Mullion full width Modeled as Jamb full width Modeled as Modeled as Sill Jamb full width full height Figure 8 89 Curtain wall simulation model represented by dotted lines to match testing THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 92 8 SPECIAL CASES 8 9 Site Built fenestration products Curtain Walls Window Walls and Sloped Glazing Steps in Modeling Curtain Walls for Rating Simulation In WINDOW Create glazing systems in WINDOW as usual with Tilt set to 90 In THERM Draw the cross sections for curtain walls in the same manner as any other model in THERM it will be a model similar to a meeting rail The following discussion lists the steps for making cross sections for intermediate horizontal and vertical frames In the example the horizontal frame and vertical frame are the same so only one drawing will be needed Figure 8 90 C
331. ned for any angle of incidence the default and most commonly used reference is normal incidence solar radiation NFRC rated SHGC s are at 0 incidence The SHGC refers to total fenestration product system performance and is an accurate indication of solar gain under a wide range of conditions SHGC is expressed as a dimensionless number from 0 to 1 0 A high SHGC value signifies high heat gain while a low value means low heat gain 3 4 3 Visible Transmittance Visible transmittance is the amount of light in the visible portion of the spectrum that passes through a glazing material This property does not directly affect heating and cooling loads in a building but it is an important factor in evaluating energy efficient fenestration products Transmittance is influenced by the glazing type the number of layers and any coatings that might be applied to the glazings These effects are discussed in more detail later in this chapter in conjunction with a review of various glazing and coating technologies Visible transmittance of glazings ranges from above 90 percent for water white clear glass to less than 10 percent for highly reflective coatings on tinted glass Visible transmittance is an important factor in providing daylight views and privacy as well as in controlling glare and fading of interior furnishings These are often contradictory effects a high light transmittance is desired for view out at night but this may create glare at times Th
332. ng system Orientation Down Spacer Draw spacer Single spacer for multiple glazings Maternal Fiberglass PE Resin Default Boundary Conditions f Use U factor values C Use SHGC values Exterior Boundary Condition Interior Boundary Condition Use existing BC from library select below Use convection plus enclosure radiation r NFR 100 2010 Exterior Figure 8 6 Insert the 24 glazing system THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 5 8 SPECIAL CASES 8 2 Meeting Rails 6 Add spacers and create materials linked to the glazing system cavity if necessary Add spacers and link materials to the glazing system cavity Figure 8 7 Add custom spacers THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 6 8 SPECIAL CASES 8 2 Meeting Rails 7 Define the boundary conditions by pressing the Boundary Conditions toolbar button or clicking on the Draw Boundary Conditions menu choice or pressing the F10 key Make sure that the interior boundary conditions are set to Radiation Model AutoEnclosure Assign the Edge U factor tag to each of the interior glazing system boundary conditions as shown in Figure 8 8 gt BC Adiabatic U factor Tag None BC lt glazing system name gt U factor Inside Film Radiation Model AutoEnclosure U factor Tag None BC NFRC 100 2010 Exterior U factor Tag None BC lt glazing system name gt U factor Inside Film Radiation Model
333. ng Database IGDB spectral data imported into the WINDOW Glass Library Glazing Systems that use approved spectral data will have a in the Mode field as shown in the figure above with the exception of laminates and applied films see Section 8 for more information The U factors shown in the Glazing System Library are based on a one meter default height When these glazing systems are used in whole products in the Window Library the center of glazing U factors will be recalculated based on the actual product height specified in the Window Library Therefore the U factors in the Glazing System and Window Libraries will probably be slightly different 1 2 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 7 TOTAL PRODUCT CALCULATIONS USING WINDOW 7 4 Overall Product U factor SHGC VT and CR Calculations Glazing System Library ID 8 Mame Sample Gle5ys H Layers 2 Tilt 90 ll Height 1000 00 mm Environmental a Conditions FPE 100 2070 IG width 1000 0 mm Comment a i 1 2 Options Thermal Calcs Optical Calcs Optical Data Overall thickness 26 510 mm Mode ee ID Mode Thick Flip Tol AReoll Aeol Awis Unit system 0 IP 5 z Glass 1 9803 CLEARS LOF 50 Jorge 0074 0074 0868 0 082 Gap1 FP 1 Ai 165 O Language choice Chinese HI 50 Q 0676 0117 0105 0 826 0115 Hame Tvis Misc options Glazing System U factor is based on the glaz
334. ng sections If the product is NOT a single or double hung i e it is a casement fixed picture transom awning etc do the following In WINDOW Create a three layer glazing system with the correct spacing between each of the glass layers in WINDOW In THERM Draw the frame components for the product in THERM Import the glazing system into THERM Edge of Glass Dimension 63 5 mm 2 5 inch Glazing System Height 150 mm 6 0 inch Fill the air cavity below the glazing system and use the Library Create Link feature to link that air cavity to the glazing cavity Assign the boundary conditions Exterior Boundary Condition Use existing BC from library select NFRC 100 2001 Exterior and assign the SHGC Exterior U factor tag to the exterior frame components Interior Boundary Condition Use convection plus enclosure radiation for Glazing System use appropriate convection only frame boundary condition for the frame components Simulate the problem THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 45 8 SPECIAL CASES 8 4 Storm Windows If the product IS a hung or sliding window i e a vertical or horizontal slider where there will be a different gap width between the glazing system and the storm window for different frame profiles do the following In WINDOW Before starting the program open the W6 INI file and add the following line if it does not already exist FrameToleran
335. ng system from the Glazing System Library as shown in the figure below a Window Library C Program Filesi LBNL WINDOW63 Aluminum Slider mdb J Ioj x Fie Edit Libraries Record Tools View Help Cee SEO AE EER Oi E A a List ID fi Calc F9 Name Aluminum 3mm CIG 5 Mode NFRC Type Horizontal Slider gt Width 1500 mm Delete Height 1200 mm Save Area 1 800 m2 Report Tit 30 Environmental Conditions NFRC 100 2010 a i kekeke Copy Dividers az 35 ola lt 3 o j 5 m ai Total Window Results U factor 2 9194 W m2 K Click on a component to display characteristics below r Glazing System 0 4728 ae Detail Name 3mm CIG gt vt 0 3485 inf 1 Ucenter LEIS W mK cR 27 Detail Ntayers 2 sc 0685 Area 0 493 m2 SHGC 0 596 Edge area 0 200 m2 Vite 0 452 2A Mode NFRC SI NUM Ai For Help press F1 Figure 9 23 Window Library record for the aluminum horizontal slider THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 9 27 9 3 Problem 2 Aluminum Horizontal Slider Window 9 SAMPLE PROBLEMS The table below shows the overall product U factor from WINDOW for Glazing Option 1 Table 9 12 Total product U factor Glazing Options Total Product U Factor 25 4 mm 1 overall thickness 9 3 6 Individual Product SHGC and VT using SHGC 0 amp 1 and VT 0 amp 1 The methodology for determining
336. nt Frit Simulated Sandblast 1086 70 Coverar Hexcel Screene 52 32 White Pearl 54 9 GreenScreen Eco 3 Pewter Platinum 54 2 Aanufacture BSOF BSOF Figure 8 188 Select the desired records to be imported into the Shading Layer Library The selected records will be imported into the Shading Layer Library Shading Layer Library C Users4rdmitchell D ocuments My Detailed View Venetian 445 Venetian 490 Venetian BO Venetian B45 Venetian B90 Venetian CO Venetian C45 Venetian COO Venetian C30 Venetian DO Venetian D45 Venetian D90 white Frit Clear Frit no pigment Slim White WB Closed Slim White Open Advanced 19 records found Export Report Print Viraspan TM Medium Gray 0 948 304 Simulated Sandblast Y 1 086 r0 Dropbox snfrc Traning B TE NFRAC Training for Software Approval Comples Producth ame Slim White Venetian Blind Slim White Venetian Blind Viraspan TM Ceramic Frit Medium Gray 0 948 30 Coverage Translucent Frit Simulated Sandblast 1086 0 Coverage Manufacturer ISO 15099 appendix ISO 15099 appendix ISO 15099 append ISO 15099 appendix ISO 15099 appendix ISO 15099 appendix ISO 15099 appendix ISO 15099 appendix ISO 15099 append ISO 15099 appendix ISO 15099 appendix ISO 15099 appendix ISO 15099 appendix Generic Generic Pella Pella Viracon Viracon Figure 8 189 The records selected from the CGDB will be imported into the WIN
337. ntal meeting rails found in vertical sliding products THERM will not calculate the Condensation Resistance for a file with the Cross Section Type set to Vertical Meeting Rail There are two methods for calculating the Condensation Resistance information in THERM which will be used in WINDOW to calculate the total Condensation Resistance of the product Check the Use CR Model for Window Glazing System checkbox when importing a glazing system OR In the Options menu Preferences choice THERM File Options tab check the Use CR Model for Glazing Systems as shown in the figure below Sti Preferences Drawing Options Simulation Therm File Options Snap Settings Mesh Control Quad Tree Mesh Parameter ig W Run Error Estimator Maximum Error Energy Morn i 0 Maximum lterations M Use CA Model for Glazing Systems Figure 8 10 In Options Preferences Iherm File Options check the Use CR Model for Glazing Systems checkbox When the CR model has been turned on red boundary conditions will appear inside the glazing system and the following steps should be taken to simulate the file 1 Check the emissivities of these boundary conditions They should be the following Emissivity of the surrounding surface such as 0 84 for standard glass 0 90 for most frame materials 0 20 for metal and so forth 1 0 for the adiabatic open end of the glazing cavity Actual cavity
338. ntegral Add Venetian Blind Hardware Add the head rail assembly of the venetian blind between the polygon representing Dtop and the polygon representing the Venetian blind Fill in the remaining cavities by linking them to the appropriate glazing system cavity Use the 5 mm rule to divide up this cavity as needed Then use the Fill tool to make a polygon that can be linked to the glazing system cavity Pull the polygon representing the Venetian blind up to meet the head rail assembly hardware or use the Fill tool to fill the cavity then link it to the Venetian blind polygon Link this polygon to glazing cavity 2 because the throat where the two cavities connect is gt 5mm See Section 6 4 4 for more details about linking cavities This polygon is modeled as a frame cavity because the throat where it connects to the glazing system cavity is lt 5 mm wide See Section 6 4 4 for rules about linking cavities to glazing system cavities Glazing cavity 1 Glazing cavity 2 This polygon is linke to glazing system cavity 1 below because the throat connecting the two cavities is gt 5mm Link this polygon to glazing cavity 2 because the throat where it connects to the glazing system cavity is gt 5 mm wide See Section See Section 6 4 4 for 6 4 4 for rules about linking more details abo t polygons to glazing cavities linking cavities Figure 8 171 Fill the remaining cavities and link to the app
339. o not reference any other libraries However the Glazing System and Window Libraries reference many of the other libraries So for example in order to export to another database all the information for a glazing system WINDOW6 must also import the referenced records from the Gas Library Glass Library and Environmental Conditions Library But the important point is that only the needed records in each of these referenced libraries are needed in the exported database So there might only be two or three entries in the Glass Library i e those used in the Glazing System instead of the 3500 entries that are in the entire database This will then make the database these records are imported into much smaller Window Library Glazing System Library Gas Library Glass Library Frame Library Environmental Conditions Library Divider Library Environmental Conditions Library Figure 7 11 The database hierarchy in the WINDOW project database THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 7 13 7 5 Project Databases 7 TOTAL PRODUCT CALCULATIONS USING WINDOW The steps to save a WINDOW database in this manner are the following Select the Library level that the export should start from in general the most complete level to export from will be the Window Library Start from the Window Library this will mean that records from all the libraries that are used either directly or indirectly from those libraries will be includ
340. oatings must be placed in a sealed air space because they would not survive exposure to outdoor elements finger prints or cleaning agents Pyrolytic coatings that are created with a high temperature process as the glass is formed are extremely hard and durable and can be placed anywhere Each location produces a different visual and heat transfer effect Other advanced coatings such as low emittance and spectrally selective coatings are normally applied to double glazed or triple glazed fenestration products These applications are discussed later in this chapter 2 8 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 2 FENESTRATION PRODUCTS 2 6 Improved Glazing Products Double pane units can be assembled using different glass types for the inner and outer layers Typically the inner layer is standard clear glass while the outer layer can be tinted reflective or both The solar heat gain coefficient is reduced because the tinted glass and clear glass both reduce transmitted radiation In addition this design further reduces solar heat gain because the inner clear glass the gas fill and any Low E coating keep much of the heat absorbed by the outer glass from entering the building interior OUTSIDE INSIDE Air or Gas Surface 1 _ Surface 3 Surface 2 Surface 4 Metal spacer Butyl primary sealant Desiccant Urethane secondary sealant Figure 2 2 Insulating Glass Unit IGU 2 6 5 Gap Width in Multiple Glazed
341. of the divider in this example it is 9 525 mm 0 375 inches Edge of Glass Dimension 63 5 mm 2 5 inches Glazing System Height 150 mm 6 0 inches Draw spacer Not checked THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 32 8 SPECIAL CASES THERM 6 3 TrueDividedLite THM E File Edit view Draw Libraries Options Calculation Window Help 8 3 Dividers O x 18 x Cees LSet Material Ti Bz EU Set Boundary Gondition F3 Material Library Shift F4 Boundary Condition Library Shift F5 St ep 1 Gas Library Shift F6 Select Material Boundary Condition Glazing Systems UFactor Names Insert Glazing System Orientation Up Greate Link Remove Link Glazing system width 18 796 mm Glazing System 9 Double Clear 4 Kefi 0 066900 Wi rn H Layers 2 Ucenter 2 73 NFAC CMA Close WINDOW Glazing System Library C Program Files LBNL INDO ES Browse Window 6 Database Wi fre B Thickness f 6 796 mm Shading layers None Spacer Draw spacer Single spacer for multiple glazings Material Fiberglass PE Resin be Default Boundary Conditions f Use U factor values f Use SHGC values Exterior Boundary Condition Use existing BC from library select below NFRC 100 2010 Exterior kyi mm Prov THERM 6 3 TruecDividedLite THM AB fie Edt View Draw Lbranes Options Calloulstion Wind
342. of the glazing system boundary conditions If this happens they can be reassigned from the Boundary Condition Library 6 34 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 6 MODELING FRAME AND EDGE HEAT TRANSFER WITH THERM 6 5 Defining Boundary Conditions Exterior Interior BC lt glazing system gt U factor Inside Film Radiation Model AutoEnclosure BC NFRC 100 2010 Exterior U factor tag None U factor tag None 150 mm 6 0 inches BC lt glazing system gt U factor Inside Film Radiation Model AutoEnclosure U factor tag Edge 63 5 mm 2 5 inches For glazing system below the sight line BC lt glazing system gt U factor Inside Film Radiation Model AutoEnclosure U factor tag Frame Interior ee Sah line ee BC Interior lt frame type gt Convection only Radiation Model AutoEnclosure BC NFRC 100 2010 Exterior U factor tag Frame U factor tag SHGC Exterior In order to model the Radiation Enclosure EAEAN x make sure all interior boundary conditions iati Bound q have the Radiation Model set to Condition Interior WoodYingl Frame convection only i i AutoEnclosure This will cause THERM to er model the Radiation Enclosure without an See Frame Cancel enclosure geometry being drawn and the Boundary l T ture 21 0 C He l244 9 Wem2 K eee convection only film coefficients for these ait i i Condition Library boundary conditions will be calculated an
343. olerance fe 006 Relaxation Parameter i M Automatically adjust relaxation parameter Adjustment step on Maxinun iterations a I View Factor Smoothing W 150 15099 Jamb Cavity Radiation Fix Save Simulation results in THM files Save Conrad results file 0 Save simulation intermediate files T Automatically increment mesh parameter Maimun entries in simulation log file 200 Mesh void tolerance li mm Cancel Apply Figure 6 33 Simulation option settings 6 40 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 6 MODELING FRAME AND EDGE HEAT TRANSFER WITH THERM 6 6 Calculating Results 6 6 4 Calculations When a calculation is started THERM can do the calculations in the background while another model is being worked on There is also a Calculation Manager accessed from the Calculation Calc Manager menu option that allows the submittal of many files at one time to be calculated in the order they are added The Calc Manager Log shows whether the jobs ran or not Calculating Multiple Glazing Options If a base case file has been created with multiple glazing options see Section 6 4 3 Multiple Glazing Options when the file is simulated using the Calc toolbar the Calculation Calculation menu option or the F9 shortcut key the Glazing Option Simulation dialog box will appear with the following options as shown in Figure 6 34 Create the glazing option files and perform all simulations This
344. on Model Blackbody U factor tag None BC 3 mm Vinyl U factor Inside Film Radiation Model AutoEnclosure U factor tag None L BC Adiabatic U factor tag None x U factor delta T Length Wi me k mm Fotation E Frame 2 6050 39 0 25 4 30 0 Projected in Glass Plane Edge fi 93986 39 0 fi af faoa Projected in Glass Plane SHGC Exterior 2 0858 39 0 25 4 o o Projected in Glass Plane E t Z Eror Energy Norm f20 POT lt Figure 9 5 THERM cross section and U factor results for the divider cross section 9 8 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 9 SAMPLE PROBLEMS 9 2 5 Total Product U Factor In WINDOW import the THERM cross sections into the Frame Library Frame Library C Program Files _LBSL WINDOW63 in l mdb File Edit Libraries ee ea Detailed View Update Copy Delete View Help Vinwl Head THM Vin amb THR Ye TY acer 4d gt wn Bae oF Frame Library C Program Files LENLAWINDOWES SY ing mdb Frame Uvalue ae ne K Therm Head 1 604 Therm Jamb 1 650 Therm Sil Source Type TAER Edge Uvalue Wi m e 2 115 2 118 9 2 Problem 1 Vinyl Fixed Window B x Edge lazing Correlation Thickness mm HA 15 1 HA 15 1 Advanced 3 records found Import Export Report Print El Mode NFRC SI NUM 4 For Help press F1 Figure 9 6 THERM files imported into the F
345. on Model Blackbody U factor tag None 63 5 mm BC lt glazing system gt U factor Inside Film 2 5 inches Radiation Model AutoEnclosure U factor tag Edge BC NFRC 100 2010 Exterior Radiation Model Blackbody U factor tag SHGC Exterior BC Interior lt frame type gt Convection only Radiation Model AutoEnclosure U factor tag Frame BC lt glazing system gt U factor Inside Film Radiation Model AutoEnclosure U factor tag Edge BC NFRC 100 2010 Exterior Radiation Model Blackbody U factor tag None BC lt glazing system gt U factor Inside Film Radiation Model AutoEnclosure U factor tag None Figure 8 93 Curtain Wall Mullion Boundary Conditions mull_boundary thm THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 96 8 SPECIAL CASES 8 9 Site Built fenestration products Curtain Walls Window Walls and Sloped Glazing Modeling Curtain Wall Jambs In this example the curtain wall jambs are modeled using the same drawing as the mullion The boundary conditions are adjusted to capture the heat flow of only half the width Since the sections may be asymmetrical both the left and right portions of the mullion are required to be simulated as left and right jambs For the Right Jamb Copy the vertical mullion drawing with boundary conditions assigned In Therm File Properties File Properties set the Cross Section Type to Vertical Meeting Rail Do not change the Boundary
346. on is used for any surface assumed to have no heat flow This is used for the top of the glazing system at the boundary between the edge of glazing and the center of glazing because the assumption is that the heat transfer between the two sections are independent of each other Adiabatic is also used for the bottom of the frame that would sit in the mask wall of the thermal chamber during testing x Boundary k Condition sample sil S ample GlzSys ID 8 U factor Ins i i U Factor Surface Edge I Cancel Temperature 69 8 F He 0 46 Btu h ft2 F Co a aN Radiation Model AutoEnclosure u Factor TEF Emissivity 0 840 Library Shading system modifier None z l Blocking Surface Default Boundary Conditior sample sil S ample GlzSys ID 8 U factor Inside Film The Default Boundary Condition field shows the default boundary condition that THERM will use when the glazing system is inserted for both interior and exterior boundary conditions If a glazing system boundary condition is changed that new boundary condition will become the default value for that THERM session Figure 6 25 Double click on a boundary condition segment to see its characteristics THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 6 29 6 5 Defining Boundary Conditions 6 MODELING FRAME AND EDGE HEAT TRANSFER WITH THERM THERM has a Boundary Condition Library accessed from the Library Boundary Conditions menu or by double c
347. on of laminated glass However in this configuration since the Low E surface is not exposed to an air space there is no effect on the glazing U factor 2 6 10 Gas Fills Another improvement that can be made to the thermal performance of insulating glazing units is to reduce the conductance of the air space between the layers Originally the space was filled with air or flushed with dry nitrogen just prior to sealing In a sealed glass insulating unit air currents between the two panes of glazing carry heat to the top of the unit and settle into cold pools at the bottom Filling the space with a less conductive gas minimizes overall transfer of heat between two glass layers Manufacturers have introduced the use of argon and krypton gas fills with measurable improvement in thermal performance Argon is inexpensive nontoxic nonreactive clear and odorless The optimal spacing for an argon filled unit is the same as for air about 1 2 inch 12 mm Krypton has better thermal performance but is more expensive to produce Krypton is particularly useful when the space between glazings must be thinner than normally desired for example 1 4 inch 6 mm A mixture of krypton and argon gases is also used as a compromise between thermal performance and cost Filling the sealed unit completely with argon or krypton presents challenges that manufacturers continue to work on A typical gas fill system adds the gas into the cavity with a pipe inserted throug
348. on only U factor surface tag Frame o BC NFRC 100 2010 Exterior U factor surface tag SHGC Exterior Figure 6 26 Defining the boundary conditions for a cross section Taped during testing so modeled with a frame cavity The upper section of this frame is thermally broken while the lower section is not The surface area of the non thermally broken frame is greater than the surface area of the thermally broken section therefore the entire frame X is tagged as non thermally broken Interior Aluminum Frame BC Adiabatic U factor surface tag None THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 6 31 6 5 Defining Boundary Conditions 6 MODELING FRAME AND EDGE HEAT TRANSFER WITH THERM 6 5 2 Assigning Boundary Conditions and U factor Surface Tags Boundary conditions for a cross section are created in THERM by pressing the Boundary Condition toolbar button clicking on the Draw Boundary Conditions menu option or pressing the F10 key THERM will automatically assign boundary conditions both interior and exterior to a glazing system imported from WINDOW as discussed above However the frame boundary conditions must be assigned in most cases NFRC 100 2010 Exterior for the entire exterior surface of the glazing system and frame Adiabatic for bottom of the frame Interior Frame Components The appropriate interior convection only boundary condition for all other interior surfaces fro
349. on to import all the records in the CGDB file E C Users Public LBNL LBNL Shared W63 CGDB 1 2 mdb eml Cancel Select All Clear selection Find ID 105 records found ID Mame Froduct ame Aanufacture b 5000 Viraspan TM Medium Gray 948 30 Viraspan TM Ceramic Frit Medium Gray 948 30 Coverage Viracon Fritted glass 5001 Simulated Sandblast 1086 70 Translucent Frit Simulated Sandblast 1086 r02 Coverage Wacon Fritted glass food Hescel Screens 52 34 White Pearl W S Hescel Screeng 52 32 White Pearl 54 9 Npsar BSDPF 6001 GreenScreen Eco 3 Pewter Platinum WS GreenScreen Eco 32 Pewter Platinum 54 2 Near ESDOF Figure 8 181 Select the desired records to be imported into the Shading Layer Library THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 194 8 SPECIAL CASES Shading Layer Library C Users4rdmitchell D ocuments My Detailed View Dropbox snfre Traning B TE AM FARC Training for Software Approval Complex Advanced 19 records found Export Report Print Venetian 445 Venetian 490 Venetian BO Venetian B45 Venetian B90 Venetian CO Venetian C45 Venetian COO Venetian C90 Venetian DO Venetian D45 Venetian D90 white Frit Clear Frit no pigment Slim White WE Closed Slim White Open Viraspan TM Medium Gray 0 948 304 Simulated Sandblast Y 1 086 r0 Slim White Venetian Blind Slim White Venetian Blind The selected records will be importe
350. or NFRC certified simulations using the following criteria The substrate for the applied film cannot have embedded coatings where embedded coatings are defined as a coating on a substrate that touches the applied film Only NFRC glass layers with the NFRC approval indicator can be used as the substrate for applied film layers The glass layers used as the substrate for the applied film can be tinted or coated as long as the coatings do not face the applied film Only the layers of the Type Applied Films in Optics that have a on them and are also on the Approved Applied Films List updated by LBNL with every IGDB release and available on the WINDOW Knowledge Base website can be used This means that the data for those applied films was submitted to the IGDB using the criteria specified in Section 1 2 of this document and that the Applied Film manufacturers are participating in the NFRC rating program For NFRC verification of the laminate construction submitted by simulators Glass Layers with an applied film constructed by simulators in Optics will not have a next to them when imported into WINDOW The simulator shall specify in simulation reports the NFRC ID s of the applied film and the substrate which shall all meet the criteria such as 2802 5038 The simulator shall provide the properties for the applied film layer including solar transmittance solar T visible transmittance photopic T sola
351. or convective film coefficients shall be constants which depend on frame material type these shall be determined using the algorithms in ISO15099 and using representative frame surface temperatures for each frame material type to be included in the Simulation Manual In section 8 3 2 the formula from this section shall be applied to all outdoor exposed surfaces Section 8 4 2 presents two possible approaches for incorporating the impacts of self viewing surfaces on interior radiative heat transfer calculations NFRC shall use the method in section 8 4 2 1 Two Dimensional Element To Element View Factor Based Radiation Heat Transfer Calculation This is also the method referenced in NFRC 500 for CI calculations Furthermore in the interests of consistency and accuracy this method shall be used for all products including planar products for U factor calculations as well as CI calculations The use of this method makes the use of Slightly or Partially Ventilated cavities see section 6 7 1 on the interior of frame surfaces redundant The standard frame convective film coefficients hc referenced in 6 above will thus be applied to all interior frame surfaces June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual APPENDIX B REFERENCES 1997 ASHRAE Handbook of Fundamentals American Society of Heating Refrigerating and Air Conditioning Engineers Inc Atlanta GA Arasteh D K Finlayson E U and Huizenga C 1994 WINDOW 4 1 A PC P
352. ord Shading Laver Library ID 5001 Name Simulated Sandblast v 1086 70 Product Mame Translucent Frit Simulated Sandblast 1086 7 Manufacturer Miecon Type Faaa E The Glass substrate cannot be changed Frit coverage enter the appropriate value if it is different than the default from the CGDB esl The referenced Glass substrate 9803 CLEAR5 LOF optical data files ea Gea E Dropbos nfrcS Training 6 TE Frit coverage m will automatically be imported into ID Name Producth ame Source Frit optical data the Glass Library jaog ELi e D 60000 1086Specular bl Translucent Frit Simulated Sar CGDB v1 01 Diffuse 160001 1026Diffuse Ibl l 6000 1086Diffusze lbl Translucent Frit Simulated Sar CODE v1 01 gogga 9485pecular lbl Viraspan TM Ceramic Frit Med CGDB v1 01 gopa 46D use Ib Viraspan TM Ceramic Frit Med CODE v1 01 Figure 8 183 The necessary records will be imported into the Glass Library for the frit layer THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 196 8 SPECIAL CASES 8 15 Frits 2 Glazing System Make a glazing system with the frit layer e Select Shade or Frit from the pulldown to the left of the layer you want to make a frit Glazing System Library ID 26 Name Sandblast Fit Layers e 8 Tilt 30 IG Height 1000 01 1000 00 ram enonmental FRC 100 2004 IG Width 1000 00 mm Comment Overall thickness mm Mode poy ILD Mame Mode Thick Flip Tal Aso Rs
353. ords will represent different geometries of the Venetian blind such as slat thickness width and slat spacing However if you are modeling the same Venetian blind product but witha different slat thickness width or slat spacing you can make a new Shading Layer Library and change the slat geometry In this example the Venetian blind has three records in the CGDB Shading Layer Library representing three different slat tilts Closed 45 degrees and Open For NFRC certification the 45 degree geometry is not needed and therefore only the Closed and Open records are imported from the CGDB as shown in the figure below Shading Layer Library C Users Public Lb LAWN DOW Erw Bv enetian mdb ID Mame Product ame Manuracturer Type Material Openness Source 3000 9 Slim White VB Closed Slim White Venetian Blind Pella Venetian White Venetian Blind Slat white txt goog CODE 3001 Slim White WB 45 Slim White Venetian Blind Pella Venetian White Venetian Blind Slat white bet o500 CODE S002 Slim White Open Slim White Venetian Blind Pella Venetian White Venetian Blind Slat white tst 1 000 CODE 2003 Slim Marine Closed Slim Marine Blue Yenetian Blin Pella Venetian Marne Venetian Blind Slat mannet goog CODE 3004 Slim Marine 45 Slim Marine Blue Yenetian Blinn Pella Venetian Marine Venetian Blind Slat marinet g5o0 CODE 9005 Slim Marne Open Slim Marine Blue Venetian Blin Pella Venetian Marne Venetian Blind Slat mannet 1 00
354. oss Sections 6 MODELING FRAME AND EDGE HEAT TRANSFER WITH THERM If during testing the product is sealed at the inside surface with tape those cavities must be simulated with the standard Frame Cavity NFRC 100 material Open cavities which would be sealed during testing must be filled with a polygon of material Frame Cavity NFRC 100 Figure 6 13 Cavities open to the interior are filled with Frame Cavity NFRC 100 material 6 3 8 Modeling Sloped and Curved Surfaces Because the exact geometry of sloped surfaces can be modeled in THERM there is no need to change the boundary conditions for sloped surfaces For curved surfaces THERM approximates curves with line segments The number of line segments used in the curve will determine how close the final model is to the original geometry of the product When importing a DXF file the number of line segments is set using the Arc to Polygon setting in the Options menu See the section on Interpreting Arcs in the Drawing Tips document on the LBNL THERM Documentation website for a detailed discussion of this procedure In general an Arc to Polygon setting of 45 degrees for small rounds and fillets in extrusions will give great enough accuracy without introducing unnecessary detail For larger curved details all points on the represented line must be within 5 mm of the actual line or curve The averaged distance for all points between the represented line and the actual line or cur
355. oundary Condition Use convection plus enclosure radiation Figure 8 62 Insert the glazing system June 2013 5 x lE x Step 4 Glazing system is inserted Step 5 Add the spacer 8 62 8 SPECIAL CASES 8 5 Skylights Note If using the Multiple Glazing Options feature of THERM set up the multiple glazing options before tilting the profile so that all the Boundary Conditions become defined automatically for the glazing options by THERM Then tilt the cross section 3 Assign Boundary Conditions and U factor tags Click on the Boundary Conditions BC toolbar button and correct any problems encountered with the geometry see Section 6 5 3 Voids Overlaps and Bad Points in this manual 4 Tilt the cross section to be 20 degrees off the horizontal plane For this example sill cross section click on the Draw menu Rotate Degree choice and enter 70 degrees Clockwise oxi amp File Edit view Draw Libraries Options Calculation Window Help lj x D Saali Polygon F2 aql f E UK Rectangle F3 Boundary Conditions F10 Fill void Insert Point Shitt Fe Delete Point Del te ioi xi Move Polygon Fil E File Edit Yiew Draw Libraries Options Calculation Window Help 18 x Tape Measure F amp DSHS Bbo tiayrraQqgegy amp F eul Set Drawing Scale Shift F8 Set Origin Shift F7 Repeat mode Locator Shift F2 Flip Left 90 Right 90 Clear Bad Points Rotate
356. oundary conditions and U factor tag tags THERM File Properties Cross section Type Sill Gravity Arrow Down BC Adiabatic BC NFRC 100 2010 Exterior U factor tag None U factor tag SHGC Exterior BC Interior lt frame type gt convection only Radiation Model AutoEnclosure U factor tag Frame Model the greater of 63 5 mm 2 5 or 25 4 mm 1 of core material consistency from bottom edge of wood framing member Height of weatherstrip BC Adiabatic st U factor tag None Figure 8 99 Bottom Rail Model THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 106 8 SPECIAL CASES 8 10 Garage Rolling Doors 8 10 1 3 End Stile Model A nominal 2x4 wood block is used in the End Stile Model The projected frame dimension shall incorporate a 1 uniform section of the garage door panel Any non continuous hardware such as rollers shall not be included in the model The boundary condition type and the U factor tag used on the End Stile model are shown in the figure below THERM File Properties Cross section Type Jamb Gravity Arrow Into the Screen BC Adiabatic U factor tag None BC Interior lt frame type gt convection only Radiation Model AutoEnclosure BC NFRC 100 2010 Exterior U factor tag Frame U factor tag SHGC Exterior Model the greater of 63 5 mm 2 5 or into 25 4 mm 1 of core material consistency from outside edge of woo
357. ow Heip CA cavity height fioo0 mm Step 3 Sight line to bottom of glass 3 525 mm Set Glazing System Spacer height 3 525 aan e properties Edge of Glass Dimension E35 mm J Set Sight line to bottom Glazing system height fi 50 mm e height ae re 7 Step a Site line to shade edge mm Edge atlass Select the appropriate glazing a 63 5 mm system from the WINDOW library 2 5 Use nominal glass thickness m Glazing system height Use CR Model for window Glazing Systems 150 mm 6 0 x Ta R Biel Defaut Custom Gap gt Condition NERC 100 width fi aR mm Interior Boundary Condition Use convection plus enclosure radiation Select Glazing Systems from the Libraries menu 2010 Exterior Interior Boundary Condition Use convection plus enclosure radiation OSS Mos tiadet agqeoe FeUKT The first glazing system is imported into the file kn 114 4 Step 10 0 imm 991 6 261 1 Ox dy 104 3 47 1 Figure 8 34 Import the first glazing system THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 33 8 SPECIAL CASES 8 3 Dividers 4 Import the glazing system again as an additional glazing system facing down this time Use the following settings for this glazing system Set the Locator in the appropriate location for where the glazing system will start in this example 3 175 mm 0 125 inches above the bottom of the divider
358. pecial Producirao a A TASE 2 10 20 9 Multiple Panes or Pris neniani ea es 2 10 20 9 LOW Emitance COUN Gs csrereoiai 2 11 26 9 1 COAUNS raceme nenna a 2 12 2O I2 COAMMNG Ty peenaa eaea A a E Aa 2 12 A E A a ATE E EEE AEE AE F ET 2 13 2 7 Thermally Improved Edge Spacers seeeesseseeseeseeeressesresressrssresresrerseesresresresees 2 14 THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 Contents 3 FENESTRATION HEAT TRANSFER BASICS cccceseseeeeeeeeeeees 3 1 De OV CV W erea aaa a aae 3 1 22 Enerey FLOW Mechans ensi anaa Na E E dale tan dentate cal sales 3 1 39 Temperature Driven Heat Tons ber errn n eee doe 3 2 Wig CON TUCO a A E A 3 3 IIa COVECE HOM ain n S 3 3 DO Radia UON eaea E A 3 3 Ae Uaa T 3 3 50 4 Ls Total Product W tactor unica e E RO 3 4 3 0 4 2 Center Of Glazine Ufa ctor sessen aaie 3 4 Dios COS EITCCUS A E N AE ETE R T E 3 4 334A Frames and Sas NOS iesin aoa a eE 3 4 IAr Overal FUME O a ree re ee reer t err rae Srrer rep h ene erntrertar 3 4 3 4 Solar Heat Gain and Visible Transmittance c cee seeesceeeseeeeseeeececeneeceneeeaees 3 5 3 4 1 Determining Solar Heat Gain eee eeseeseceeceseceseeeseeesaeeeeeenees 3 5 3 4 2 Solar Heat Gain Coefficient GHGC 0 0 eee eesceeeseeeeeeeeenneeenneeeaees 3 6 Oi Oe VISIE Transi tla in Cite se eset cancer teteneitcat a 3 6 29 SCONGENSAHOM RESIS tal Ce sac dardests fats ieee tek dgavee easdusheetactittcauabeedetieicadeomiadee utes te 3 7 3 5 1 Imp
359. pecifically to the NFRC procedures 6 3 1 Getting Started Drawings and DXF Files In order to reproduce accurate cross sections in THERM it is necessary to use dimensioned drawings and or DXF files See Section 5 2 Importing a DXF or Bitmap File as an Underlay in the THERM User s Manual If only dimensioned drawings are available assembly drawings and die drawings and there are no DXF files it is still possible to create a cross section in THERM Section 5 5 Drawing Using the Keyboard Numeric Cursor Positioning of the THERM User s Manual 6 3 2 File Properties Cross Section Type It is extremely important to specify the Cross Section Type in the THERM File Properties dialog box accessed from the File Properties menu The Cross Section Type in combination with the glazing system orientation will determine how many of the parameters in the the ISO 15099 simulation models are implemented such as the frame cavity gravity vector This setting will appear in the WINDOW Frame Library in the Type field and it also appears in the lower right hand corner of the main THERM screen Therm File Properties x Filename sample sill Directory C Program FilesS LENLAWINDOW 635 amples Creation Date Friday March 06 1996 09 21 PM Cancel The THERM version the program __ Last Modifed Tuesday August 31 2010 04 36 PM Version 6 3 5 0 was calculated in is displayed Calculated ir Results need to be recalculated Title
360. photopic Rf na Change Substrate Wavelength microns Add Coating 4dd Film photopic Ab E mitF EmitB cc Lo oo L O Transmission Refectance Fonk Reflectar cc oo E sefa HUTE TELL ce cc oo E Rename BLORN10 LOF Change Details tep 4 Select the Add Film choice from the Edit Menu OR right click on the Layer button to see the menu to add the film Glazing System Gap Width Figure 8 124 Select a monolithic glass layer click on the Layer button and select the Edit Add Film menu choice THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 135 8 SPECIAL CASES 8 12 Creating an Applied Film Layer in Optics for NFRC Certification Change Glazing Existing Glazing Filename CLEAR_3 DAT Product Hame Generic Clear Glass Appearance Cer NFRC ID io Glazing Type Monolithic Material Glass Substrate Filename INA Film N ame BLA Thickness mm 2 048 Manufacturer Generic Film applied to New Glazing Filename ELEAR_3 DAT Product Marne Generic Clear Glass Appearance Clear NFRE ID foz Glazing Type Mi lithi Sii Click on the piz izni Glass highlighted Film Substrate Filename ira Name box which will open the Select new film or applied film dialog box Film Mame Thickness mm 3048 Manufacturer Generic a Make sure to specify Apply film to the side of the Front of Glazing Exterior
361. ping procedure has been developed by NFRC It is based on Section 4 2 3 E of the NFRC 200 Standard Procedure for Determining Fenestration Product Solar Heat Gain Coefficient and Visible Transmittance at Normal Incidence To determine the SHGC grouping follow the steps below For the products with the largest and smallest daylight openings 1 7 10 Determine the SHGC for both products Using the product with the highest Center of Glass SHGC determine the whole fenestration SHGC for the product with the largest daylight opening and the product with the smallest daylight opening using equation 4 1 of NFRC 200 SHGClargest SHGCOlargest SHGCe SHGCliargest SHGCOlargest SHGCsmallest SHGCOsmallest SHGCe SHGC1 smallest SHGCOsmallest For the purpose of this procedure you must start with the glazing option with the highest Center of Glass SHGC or do this for each different glazing option or a group of glazing options always using the highest Center of Glass SHGC as the starting point Calculate the difference for both products SHGC gi f SHGCgiff SHGClargest SHGCsmallest Determine the number of SHGC groups needed NGN To determine the number of SHGC groups needed NGN for this range of products divide SHGC git by 0 05 NGN SHGCgif 0 05 Calculate the daylight area difference for both products Areagi f Calculate the difference in daylight area between the product with the largest daylight a
362. play mode Normal r Total Window Results Click on a component to display characteristics below U factor 1 8095 w m2 K Glazing System 0 5254 si Detail Name 3mm low E x gt YT 0 6435 ID 1 Ucenter 1 771 W m2 K CR 53 Detail Nlayers Z Sc 0 698 Area 1 249 m2 SHGC 0 607 Edge area 0 303 m2 Vte 0 746 gt Mode NFRC SI NUM di For Help press F1 File Edit Libraries Record Tools View Help oe sO SBli hd roma Oi OHF Name Vinyl 3mm low E with E Mode rRe Type Fixed picture gt gt gt Width 1200 mm Height 1500 mm Area 1 800 m2 Tit 30 Environmental Conditions NFARC 100 2010 Dividers Display mode Normal Glazing System 0 4585 nae Detail Name 3mm low E gt YT 0 5558 ID 1 Ucenter 1 771 W m2 K CR 53 Detail Nlayers 2 sc 0698 Area 0 345 m2 SHGC 0 607 Edge area 0 283 m2 Vte 0 746 Total Window Results Click on a component to display characteristics below U factor 1 9941 Wm2 K gt Mode NFRC SI NUM Ai For Help press F1 Figure 9 9 WINDOW total product U factor calculation with dividers The following table shows the overall product U factor from WINDOW both with and without dividers Table 9 4 Total product U factors Glazing Options19 05 mm 0 75 overall Total Product U Factor Clear Air Low E without dividers 1 8095 0 3187 Clear Ai
363. poe Figure 8 131 Venetian Blind Between Glass is a blind between two pieces of glass The following cases must be modeled for each venetian blind configuration OPEN Venetian blind fully retracted ie the most transmitting state e CLOSED Venetian blind fully deployed ie the least transmitting state THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 144 8 SPECIAL CASES 8 14 Venetian Blinds Between Glass Integral 8 14 1 WINDOW Preferences It is important to set the values correctly in the Preferences dialog box in order to produce reasonable results in WINDOW The settings should be as follows Thermal Calcs Tab e Calculation standard ISO 15099 e Integral Model ISO 15099 Set Convection Model for Integral Venetian Blind to ISO 15099 Options Thermal Calcs Optical Calcs Optical Data Updates Set Calculation Standard Thermal calculation options to ISO 15099 Calculation standard 150 15099 Convection models Outside Integral Inside Model Model Model Venetian blinds liso 15099 ISO 15099 liso 15095 Woven shades SO 15099 liso 15099 liso 15099 Figure 8 132 Preferences settings for Thermal Calcs Tab for Integral Venetian Blind Optical Calcs Tab e Use matrix method for specular systems glazing systems without shading devices unchecked e Spectral data Condensed spectral data e Number of visible bands 5 e Number of IR bands 10 e Generate ful spectrally aver
364. pper 1992 Shapiro 1983 Shapiro 1986 Shapiro 1990 and Zienkiewicz 1989 Error Energy Norm EEN determines if mesh needs to be refined See Zienkiewicz 1992a and Zienkiewicz 1992b Post processor produces temperature and heat flux results by element See Shapiro 1983 Shapiro 1986 and Shapiro Post processed results are reported See Finlayson 1998 x U factor 7 Min Max Temps Figure 4 2 THERM program calculation procedures flow chart THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 4 5 4 4 Total Product Calculations 4 SUMMARY OF ALGORITHMS 4 4 Total Product Calculations The total fenestration product properties for U factor SHGC and VT are based on an area weighted average of the product s component properties which are the center of glazing properties of the glazing system the frame edge of glazing divider Edge of divider The frame edge and divider edge properties depend on the center of glazing properties of the associated glazing system This area weighted total product value can be calculated using the WINDOW program or other calculation tool such as a spreadsheet This procedure for this area weighted calculation is 1 Multiply the component property by the component area 2 Sum these area weighted component properties 3 Divide the area weighted sum by the total projected area of the product The operator types fixed vertical slider horizontal slider casement determine wh
365. r 6mm Argon 95 Clear 8mm PPG Low E 3mm Air Clear 6mm PPG Low E 3mm Argon 95 Clear 3mm PPG 9 46 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 9 SAMPLE PROBLEMS 9 5 Problem 4 Door 9 5 3 Center of Glazing Modeling WINDOW In WINDOW create four records for the glazing systems described in the glazing matrix The figure below shows the WINDOW Glazing System Library for this glazing system ss Glazing System Library C Program Files LBNL WINDOW63 Door mdb iol x File Edit Libraries Record Tools View Help Cee ts PRESB in r gt wn Baelpi Hl Glazing System Library C Program Files LBNL WINDOW63 D oor mdb Detailed View Calc of i Environmental Overall Layers Mode Tilt Conditions Keff Thickness SHGC New wm K mm Se ae NFRC 100 2001 go43 DN 3142 0 754 Copy 3 mm Clear_Argon_Clear H go NFRAC 100 2001 0 036 12 20 i 0 755 Delete 3 mm Low e_Air_Clear H go NFAC 100 2001 0 025 12 20 0 399 Ene 3 mm Low e_Argon_Clear H g0 NFRAC 100 2001 0 018 12 20 f 0 394 ID Advanced 4 records found Import Export Report Print ba For Help press F1 Mode NFRC SI NUM j Figure 9 43 WINDOW Glazing System Library for the door The results for the center of glazing U factors are shown in Table 9 35 Table 9 25 Center of glazing U factor results from WINDOW Glazing Options Center of glazing U Factor 12 7 mm 0 5 overall thickness BTU hr ft2
366. r Low E with dividers 1 9941 0 3512 9 10 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 9 SAMPLE PROBLEMS 9 2 Problem 1 Vinyl Fixed Window 9 2 6 Individual Product SHGC and VT using SHGC 0 amp 1 and VT 0 amp 1 The methodology for determining the Solar Heat Gain Coefficient SHGC and Visible Transmittance VT for products is outlined in NFRC 200 using values of SHGCo SHGCi VTo and VTi A detailed explanation of how to apply that methodology in WINDOW is presented in Section 7 4 1 of this manual These values are calculated in WINDOW for the best glazing option modeled with the highest frame and edge U factor frame as outlined in NFRC 200 Section 4 2 3 A The values calculated from that one case are then used to calculate the SHGC and VT for any other glazing options using Equations 4 1 and 4 2 in NFRC 200 Do not use the SHGCo SHGC1 VTo and VTi from WINDOW for every glazing option just for the best glazing option Using this procedure display the results for the SHGCo SHGCi VTo and VT for the best glazing option Clear Air Low E by clicking on the Detail button on the Window Library Detailed View screen as shown in the figure below The SHGC and VT detail dialog box will show the SHGC and VT values for the following three cases for this glazing option No Dividers Dividers lt 25 4 mm modeled as 19 5 mm Dividers gt 25 4 mm modeled as 38 1 mm ss Window Library C Program Files LBNL WINDOW63
367. r Inside Film Radiation Model AutoEnclosure U factor tag None BC Adiabatic U factor tag None x U factor delta T Length wwr ma E C mm Rotation SHGC Eteriar fi 4040 E 47 62495 30 0 Projected in Glass Plane Frame 1 6037 so 47 625 30 0 Projected in Glass Plane Edge 2 1151 E 63 5 30 0 Projected in Glass Plane 4 Error Energy Norm PEDE Export Haja Figure 9 4 THERM cross section and U factor results for the head cross section THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 9 7 9 2 Problem 1 Vinyl Fixed Window 9 SAMPLE PROBLEMS Divider BC Adiabatic U factor tag None Cross Section Type Vertical Divider model both vertical and horizontal dividers as Vertical Do not use the CR model with a Vertical Divider cross section Gravity Vector Into the Screen BC 3 mm Vinyl U factor Inside Film It is not necessary to apply the SHGC Radiation Model AutoEnclosure Exterior U factor tag in this case because U factor tag None the interior projected frame dimension and the exterior wetted length are the same but it should be added for consistency BC 3 mm Vinyl U factor Inside Film Radiation Model AutoEnclosure U factor tag Edge BC 3 mm Vinyl U factor Inside Film Radiation Model AutoEnclosure U factor tag Frame Gravity eckorse 4 BC 3 mm Vinyl U factor Inside Film Radiation Model AutoEnclosure BC NFRC 100 2001 Exterior U factor tag Edge Radiati
368. r air Insulating the skylight well and providing adequate air movement assists in reducing condensation Also the use of more highly insulating glazing with a well designed frame can help solve this problem In many systems a small gutter is formed into the interior frame of the skylight where condensate can collect harmlessly until it evaporates back into the room air The NERC Publication NFRC 501 User Guide to NERC 500 contains more information about condensation resistance THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 3 7 3 5 Condensation Resistance 3 FENESTRATION HEAT TRANSFER BASICS 3 5 1 Impact of Glazing Type and Spacers on Condensation Figure 3 4 indicates condensation potential for four glazing types at various outdoor temperature and indoor relative humidity conditions Condensation can occur at any points that fall on or above the curves As the U factor of windows improves there is a much smaller range of conditions where condensation will occur Figure 3 4 must be used with caution since it shows condensation potential for the center of glazing area only the area at least 63 5 mm 2 5 inches from the frame glazing edge Usually condensation will first occur at the lower edge of the product where glazing temperatures are lower than in the center As Figure 3 4 shows double glazed products create a warmer interior glazing surface than single glazing reducing frost and condensation The addition of low E coat
369. r reflectance front solar Rf solar reflectance back solar Rb visible reflectance front photopic Rf visible reflectance back photopic Rb Emissivity front EmitF Emissivity back EmitB These values are reported on the Optics screen when the laminate is calculated and also in the WINDOWS Detailed Report from the Glazing System Library This requirement can be met by submitting the Optics User Database containing the applied film glass layers with the certification documentation An IA or anyone else wanting to check the results can open the Optics User Database to verify the film and substrates used as well as recreate the applied film layer from the specified film and substrate to verify the calculated values THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 131 8 SPECIAL CASES 8 12 Creating an Applied Film Layer in Optics for NFRC Certification 8 12 2 Film Data There are two types of films in Optics the difference between them is how they were measured for submittal to the International Glazing Database Films These films were measured without a substrate and may appear in and be inputs to Optics calculations However the IGDB submittal process no longer accepts this type of submittal and they cannot be used for the NFRC Applied Film procedure Data in this category can be resubmitted to the IGDB measured as an applied film with a substrate and thus be added to the Applied Film category Applied Films T
370. r vapor that would fog the unit provide a gas tight seal that prevents the loss of any special low conductance gas in the air space create an insulating barrier that reduces the formation of interior condensation at the edge Older double pane wood fenestration products used a wood spacer that could not be hermetically sealed and thus was vented to the outside to reduce fogging in the air gap Modern versions of this system function well but because they are not hermetically sealed cannot be used with special gas fills or some types of Low E coatings Early glass units were often fabricated with an integral welded glass to glass seal These units did not leak but were difficult and costly to fabricate and typically had a less than optimal narrow spacing The standard solution for insulating glass units IGUs that accompanied the tremendous increase in market share of insulating glass in the 1980s was the use of metal spacers and sealants These spacers typically aluminum also contain a desiccant that absorbs residual moisture The spacer is sealed to the two glass layers with organic sealants that both provide structural support and act as a moisture barrier There are two generic systems for such IGUs a single seal spacer and a double seal system In the single seal system an organic sealant typically a butyl material is applied behind the spacer and serves both to hold the unit together and to prevent moisture intrusion These seals ar
371. rame Library In WINDOW two records are created in the Window Library for the U factor calculation one without dividers and one with the manufacturer supplied dividers as shown in the figure below Window Library C Program Files LBNL WINDOW63 inyl mdb p File Edit Libraries Record Tools wiew Help Dek eBeam M Bati OHZ Window Library C Program FilesSLBENLAWINDOW Ba Winyl mdb 5 x Detailed View Cale Name Type width Height Ufactor SHGC Tyis mm mm wW me k Fixed picture 1200 1500 1 809 0 525 0644 Fixed picture 1200 1500 1 995 0 459 0 556 Vinwl amm low E No Dividers E ais Vinyl 3mm low E with Dividers Delete Advanced 2 records found Import Export Report adad Frint bd Y For Help press Fl we Mode FRC ST uum Figure 9 7 Window Library records for the product with and without dividers for the U factor calculation THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 9 9 9 2 Problem 1 Vinyl Fixed Window 9 SAMPLE PROBLEMS ss Window Library C Program Files LBNL WINDOW63 inyl mdb File Edit Libraries Record Tools view Help Cod Sale Gaeli OF Z K ON List ID fi x ee Cale F9 Name Vinyl 3mm low E No Dis Mode NFRC New Type Fixed picture 7 gt Copy Width 1200 mm Delete Height 1500 500 mm Save Area 1 800 m2 Report Tilt 90 Environmental Conditions J Dividers NFRC 100 2010 Dividers Dis
372. rame on each side as needed ak ight line to bottom of glass 38 826 rim Spacer height 38 526 mm 63 5 mm Hk Edge of Glass Dimension Glazing system height mm ma Set to 0 for blind between glass this value can also be wU negative if the sightline is below the blind hardware Venetian blind hardware N li Sight line to shade edge l Use CR Polygon representing the Venetian blind Set the Sight Line to Bottom of Glass and Spacer Height to the value needed to allow room to fit the Venetian Blind hardware into the glazing system space Sightline It is always possible to edit the glazing system polygons after the fact using the Allow Editing of IG Polygons in Preferences Figure 8 155 Insert the glazing system with the Venetian blind Fill in the remaining cavities and either model them as NFRC Frame Cavities or link them to the appropriate glazing system cavity if the criteria in Section 6 4 4 are met THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 170 8 SPECIAL CASES 8 14 Venetian Blinds Between Glass Integral Use the Fill tool to fill the remaining cavities then link them to the appropriate glazing system cavity Pull the polygon representing the Venetian blind up to meet the head rail assembly hardware or use the Fill tool to create a polygon then link it to the Venetian blind polygon Link this polygon to the glazing cavity b
373. rans Tir 0 000 Emis Front Emis1 0 840 Emis Back Emis2 0 840 Conductivity 0 092 i m K Color a l Diffusing Comment zl For Help press F1 Mode NFRC SI NUM Z Figure 8 72 Create a new record in the Glass Library for the Glass Block tested value 4 Inthe Glazing System library create a record for in this example a glass block glazing system using the new glass layer created in the Glass Library and calculate the properties se Window Library C Program Files _LBNL WINDOW63 Sky light mdb IOl x File Edit Libraries Record Tools View Help Cae ela mj wer n eo eli OFZ Glazing System Library List Cale F9 Df Name Glass Block 26mm Hew Layers S Tilt 90 i IG Height 1000 mm Copy Environmental NERC 100 2010 m IGwidhf 1000 mm Delete Comment oO O O Save Overall thickness 25 603 mm Mode j Report ID Mame Mode Thick Flip Tsol Rsa Raola Twis Avis Awis Tir E1 E2 Cond Glass 1 Pe 20000 Glass Block 256 0634 0075 0 075 0 899 0 083 0 083 0000 O840 0 840 0 092 Center of Glass Results Temperature Data Optical Data Angular Data Color Properties Ufactor SC SHGC Rel Ht Gain Wet K we re 1 0018 0 8715 649 hal For Help press Fl Mode NFRC SI mum 4 Figure 8 73 Create a new record in the Glazing System Library using the Glass Block layer THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 71 8 SPECIAL CASES 8 5 Skylig
374. rature data from both the CR and U factor simulations which WINDOW uses to calculate the frame CR values shown in the Frame Library Detailed View and also the whole product CR values shown in the Window Library Detailed View When the CR model is not appropriate for the whole product CR calculations WINDOW will use the temperatures from the THERM U factor calculation instead as shown below Table 6 3 Temperatures used by WINDOW based on Product Type and Tilt Product Type WINDOW 5 Whole Product Tilt Temperatures Used by WINDOW From THERM input in Window Library for whole product CR calculations Detailed View Horizontal elements Sill Head Horizontal Meeting Rail Horizontal Divider Horizontal and Vertical elements gt 0 lt U factor Gill Head Horizontal Meeting Rail Horizontal Divider Jamb Vertical Meeting Rail Vertical Divider Vertical elements U factor Jamb Vertical Meeting Rail Vertical Divider Horizontal and Vertical elements CR not calculated Sill Head Horizontal Meeting Rail Horizontal Divider Jamb Vertical Meeting Rail Vertical Divider THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 6 25 6 4 Importing Glazing Systems 6 MODELING FRAME AND EDGE HEAT TRANSFER WITH THERM The application of these rules happens when WINDOW performs a calculation in the Window Library It is up to the simulator to have provided WINDOW with the appropriate simulations in THERM in order for
375. re used in the Insert Glazing System dialog box e Orientation Down for the Head cross section e Cross Section Type Head Setting the Cross Section Type to the approriate value allows THERM to automatically insert a polygon in the correct place for the Dtop for Head Dbottom for Sill Dright for Right Jamb and Dleft for Left Jamb e Spacer Height 0 or 38 826 mm You can use the spacer height value to make room for the Venetian blind hardware or you can set it to zero and pull the glass layers into the frame make sure Options Preferences Drawing Options has Allow Editing of IG Polygons checked e Sight Line to bottom of glass The sightline is defined by the edge of the venetian blind hardware e Sight line to shade edge In this case the sightline to shade edge is 0 because the venetian blind actually sits inside the hardware and will need to be edited to move it into place Frame or spacer element Figure 8 154 Sightline to Shade Edge definition for inserting glazing system Sightline to Shade Edge Sightline excluding shade hardware Sightline to Bottom of Glass THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 169 8 SPECIAL CASES 8 14 Venetian Blinds Between Glass Integral Insert Glazing System Orientation fees ola aE Glazing system width CR cavity height 1000 ie Once the glazing system is inserted pull the glazing system layers up to meet the f
376. rea and the product with the smallest daylight area Areadiff Areadaylightlargest Areadaylight smallest Calculate the Grouped Area Band Width GABW Divide the Area difference by the number of SHGC groups needed and round to the next integer to obtain the Grouped Area Band Width GABW GABW Areaaire NGN June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 7 TOTAL PRODUCT CALCULATIONS USING WINDOW 7 4 Overall Product U factor SHGC VT and CR Calculations 6 Determine the Sightline Group Leader The sightline group leader is the mid point of each band Group leader Areadaylight largest Group Leader Number 0 5 GABW So for example 1st group leader Areadaylight largest 0 5 GABW 2nd group leader Areadaylight largest 1 5 GABW 3rd group leader Areadaylight largest 2 5 GABW And so forth for the number of GABW calculated 7 Calculate SHGC and VT for each Sightline Group Leader Model each group leader and use the SHGCo SHGCi VTo and VT numbers to calculate the SHGC and VT for each group THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 7 11 7 4 Overall Product U factor SHGC VT and CR Calculations 7 TOTAL PRODUCT CALCULATIONS USING WINDOW 7 4 3 Whole Product U factor With Dividers The generic dividers used to calculate the SHGCo SHGC1 VTo and VT values are NOT used to calculate the whole product U factor if the whole product is manufactured with dividers In that case
377. redgasFilled THI Therm Wertical Divider Step 1 From the WINDOW Frame Export Library click on the Import button An Open window will appear Select the THERM file or files to import Report File name TrueDividedlite THM Files of type Themfiles thm O Cancel Open az read only xl Fies BNLATHERME3 Divider TrueDividedLite Cancel add Frint For Help press F1 A Step 2 Specify the record number or use the program default number which is an gt increment from the last record ID for new record 110 M Overwrite existing records Divider Library C Program Files LENL WINDOWG S Dividers mdb ioj xi File Edit Libraries Record Tools View Help D eWl eel SEE n Batel ODl e 7 Divider Library C Program Files LBNL YW IN DOWWE 3s Dividers mdb Detaled View Update E dge Edge Glazing Pid Uvalue Correlation Thickness He Wiirnie B Wr K mm mm Alum Divided ASHRAE N A MA BAA Class NA Butyl Divided ASHAAE M A N A NA Classe BA Wood Divided ASHRAE Suspended Nia N A Class3 Nd Insul Divided ASHRAE Suspended NA MA Classd NAA Alum Suspended ASHRAE Suspended Nia N A Class HA vinyl Suspended ASHRAE N A MA BAA Class N A DividerContoured THM Then Wertical Divider 1 953 1 832 N A 25 4 DividerContouredGasFiled TH Therma Wertical Divider 1 803 1 799 N A 25 4 SimulatedDividedLite THM Therm Wertical Divider 2773 NAA 18 9 J Name Source Type Uyalue Copy Del
378. reen After clear glass the gray glasses are most commonly used in residential construction as they have the least effect on the perceived color of the light Tinted glass is discussed later in this chapter The mechanical properties of glass can be altered as well as its basic composition and surface properties Heat strengthening and tempering make glass more resistant to breakage Heat strengthened glass is about twice as strong as standard glass Tempered glass is produced by reheating and then quickly chilling the glass It breaks into small fragments rather than into long possibly dangerous shards Laminated glass is a sandwich of two outer layers of glass with a plastic inner layer that holds the glass pieces together in the event of breakage Fully tempered and laminated glass is required by building codes in many door and fenestration product applications 2 5 2 Plastics Several plastic materials have been adapted for use as glazing materials Their primary uses are fenestration products with special requirements and skylights The following list of plastic glazing materials covers the major types of plastic glazing materials and compares their general properties Clear acrylic is widely available and relatively inexpensive It is available in various tints and colors It has excellent visible light transmittance and longevity However it is softer than glass which makes it vulnerable to scratching Frosted acrylic is like c
379. rences Drawing Options Then pull the edges of the glazing in the glazing gt system up to the frame Preferences Drawing Options Arc to Polygon degrees per side conversion ue i Stay in draw mode after drawing Always check for overlapping polygons IY Snap preview IY Prompt before deleting polygons When inserting the glazing system make sure the Sight line to bottom of glass includes the height of the entire Venetian blind assembly so that points will be inserted in the proper places to define the boundary conditions and U factor tags Insert a point on the outside glass surface Figure 8 140 Insert the glazing system THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 154 8 SPECIAL CASES 8 14 Venetian Blinds Between Glass Integral 4 Fill the cavities around the venetian blind with a material and then link that material to the cavity of the main glazing system There may be several cavities to be linked as shown in the figure below To link the left hand cavity next to the venetian blind to the main glazing system cavity do the following e Apply the 5 mm rule for breaking up cavities Section 6 3 6 then fill the cavity with a material any material will work e select the cavity you just filled e go to the Library menu Create Link option e the eyedropper tool will appear click on the main glazing cavity the polygon to link to and the other cavity will turn gray a
380. rior Radiation Model Blackbody U factor tag SHGC Exterior BC Interior lt frame type gt Convection only Radiation Model AutoEnclosure U factor tag None BC NFRC 100 2010 Exterior Radiation Model Blackbody U factor tag None BC lt glazing system gt U factor Inside Film Radiation Model AutoEnclosure U factor tag None Figure 8 94 Right Jamb Boundary conditions rightjamb_boundary thm THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 98 8 SPECIAL CASES 8 9 Site Built fenestration products Curtain Walls Window Walls and Sloped Glazing For the Left Jamb The process is the same as the right jamb except that the Frame edge and SHGC Exterior tags are assigned to the bottom half of the drawing and the top half is assigned the tag of none Left Jamb Exterior Interior 150 mm 6 0 inches BC lt glazing system gt U factor Inside Film Radiation Model AutoEnclosure BC NFRC 100 2010 Exterior Engel tad NORE Radiation Model Blackbody 63 5 mm U factor tag None 2 5 inches BC Interior lt frame type gt Convection only Radiation Model AutoEnclosure U factor tag None BC Interior lt frame type gt Convection only Radiation Model AutoEnclosure U factor tag Frame BC NFRC 100 2010 Exterior Radiation Model Blackbody U factor tag SHGC Exterior BC lt glazing system gt U factor Inside Film Radiation Model AutoEnclosure U factor tag
381. rogram for Analyzing Window Thermal Performance in Accordance with Standard NFRC Procedures LBL Report 35298 Berkeley CA ASHRAE Standard 142P Standard Method for Determining and Expressing the Heat Transfer and Total Optical Properties of Fenestration Products Public Review Draft October 1996 American Society of Heating Refrigerating and Air Conditioning Engineers Inc Atlanta GA Baehmann P L Wittchen S L Shephard M S Grice K R and Yerry M A 1987 Robust Geometrically Based Automatic Two Dimensional Mesh Generation International Journal for Numerical Methods in Engineering 24 1043 1078 Curcija D Power J P and Goss W P 1995 CONRAD A Finite Element Method Based Computer Program Module for Analyzing 2 D Conductive and Radiative Heat Transfer in Fenestration Systems Draft Report University of Massachusetts at Amherst Curcija D and Goss W P The Variable h Model For Improved Prediction of Surface Temperatures in Fenestration Systems DRAFT June 1998 University of Massachusetts Report Curcija D June 20 2006 Conrad 5 and Viewer 5 Technical and Programming Documentation Carli Inc Amherst MA Finlayson E U Arasteh D K Huizenga C Rubin and M D Reilly M S 1993 WINDOW 4 0 Documentation of Calculation Procedures LBL Report 33943 Berkeley CA Finlayson E U Mitchell R Arasteh D Huizenga C Curcija D 1998 THERM 2 0 Program Description A
382. ropriate glazing system cavities THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 184 8 SPECIAL CASES 8 14 Venetian Blinds Between Glass Integral Create the other cross sections in this manner Head Cross Section Sill Cross Section Jamb Cross Section Figure 8 172 Head and Sill cross sections for Closed Venetian Blind between glass layers Integral THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 185 8 SPECIAL CASES 8 14 Venetian Blinds Between Glass Integral Boundary Conditions For Integral Venetian Blinds set Shading System Modifier to None Boundary Condition Type i X Baud Ponditien venetianClosed SiltLowE DbIGlz Integral rack 5 eee Edge O Cancel Temperature 69 8 F He 0 33 Btuh tt2 F E Radiation Model AutoEnclosure U Factor Surface Library Emissivity 0 840 Shading system modifier None Figure 8 173 For Integral Venetian blinds set the Shading System Modifier to None THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 186 8 SPECIAL CASES 8 14 Venetian Blinds Between Glass Integral p BC NFRC 100 2001 Exterior U factor Tag SHGC Exterior BC NFRC 100 2001 Exterior U factor Tag None BC lt glazing system name gt U factor Inside Film Radiation Model AutoEnclosure U factor Tag None BC Adiabatic U factor Tag None Figure 8 174 Define the boundary conditions for Head Non Retractable Closed Venetian B
383. rrent updates http windows bl gov software and click on the International Glazing Database link Create a glazing system for the product to be modeled which is composed of entries from the Glass and Gas Libraries This Glazing System can then be imported into THERM to calculate the frame and edge of glazing values The Glazing System is also used in WINDOW when constructing the whole product in the Window Library Glazing System Library ID 8 Name Sample GlzSys Layers 2 Tit 90 IG Height 1000 0 mm Environmental ae Conditions INFRC 100 2010 M IG Width 1000 0 mm Comment Overall thickness 26 510 mm Mode ID Name Mode Thick Flip Tsol Rsoll Asol2 Tvis Avisl Avis2 Tir Eil E2 Cond 7 Glass 1 gt gt 9803 CLEARS LOF 50 0798 0 074 0 074 0 888 0 082 0 082 0 000 0 840 0 840 1 000 Gap1 gt gt i 165 O z Glass 2 b gt 9923 LO W E_5 LOF 50 O 0 676 0 117 0105 0826 0115 0109 0 000 0 158 0 840 1 000 Center of Glass Results Temperature Data Optical Data Angular Data Color Properties Ufactor 210 SHGC Rel Ht Gain Tvis Keff Gap 1 Keff wW m2 K Wm2 wm K wWm K 1 9319 0 7885 0 6860 510 0 7407 0 0493 0 0493 Figure 5 1 WINDOW Glazing System Library Detailed View THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 5 1 5 2 Glass Library 5 MODELING CENTER OF GLAZING WITH WINDOW 5 2 Glass Library The Glass Library contains individual glass layers that can be used to cons
384. rs the modeling procedures for products that are allowed to be certified using the simulation method as covered in the appropriate NFRC standards documents There are modeling capabilities in WINDOW 6 3 and THERM 6 3 that are not covered in the NERC documents and these cannot be used for NFRC product certification In general this manual references the User s Manuals rather than repeating the information If there is a conflict between either of the User Manual and this THERM 6 3 WINDOW 6 3 NFRC Simulation Manual the THERM 6 3 WINDOW 6 3 NFRC Simulation Manual takes precedence If this manual is in conflict with any NFRC standards the standards take precedence For example if samples in this manual do not follow the current taping and testing NFRC standards the standards not the samples in this manual take precedence NFRC periodically publishes technical interpretations to clarify or provide modeling techniques rules and procedures for simulating products in THERM and WINDOW Refer to the NERC website to review all technical interpretations THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 1 1 1 2 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 2 FENESTRATION PRODUCTS 2 1 Overview Much of the information in this chapter is taken from Residential Windows A Guide to New Technologies and Energy Performance by John Carmody Stephen Selkowitz and Lisa Heschong Although glazing materials are the focus of much of t
385. s Then pull the edges of the glazing in the glazing system up to the frame Preferences Drawing Options Arc to Polygon degrees per side conversion us p Stay in draw mode after drawing Always check for overlapping polygons IY Snap previews IY Prompt before deleting polygons When inserting the glazing system make sure the Sight line to bottom of glass includes the height of the entire Venetian blind assembly so that points will be inserted in the proper places to define the boundary conditions and U factor tags Insert a point on the outside glass surface Figure 8 145 Insert the glazing system and edit it if necessary to bring the glazing layers to the frame THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 160 8 SPECIAL CASES 8 14 Venetian Blinds Between Glass Integral 5 Fill the cavities in the double glazing system and around the venetian blind in the third glazing layer with a material any material and then link that material to the appropriate cavity the double glazing system cavity to the double glazing system and the third glazing layer cavity to the third glazing layer There may be more than one area that is linked to a cavity so make sure to link them all To link the cavity next to the venetian blind to the main glazing system cavity do the following e fill the cavity with a material any material will work e select the cavity you just filled go to the Library menu
386. s closed from the outside so that additional external wind pressure tends to push the sash more tightly shut Hinged windows require a strong frame to encase and support the projecting sash Also because projecting type sashes must be strong enough to swing out and still resist wind forces the stiffer window units do not flex as readily in the wind In addition hinged windows have locking mechanisms that force the sash against the weatherstripping to maximize compression These design details tend to reduce air infiltration of hinged windows in comparison to sliders 2 3 2 Sliding Windows Sliding windows whether single hung double hung or horizontal sliders generally have higher air leakage rates than projecting or hinged windows Sliding windows typically use a brush type weatherstripping that allows the sash to slide past This type is generally less effective than the compression gaskets found in projecting windows The weatherstrip effectiveness also tends to be reduced over time due to wear and tear from repeated movement of the sliding sash The frames and sashes of sliding units can be made with lighter less rigid frame sections since they only need to support their own weight This lightness may permit the sliding frames to flex and can allow more air leakage under windy conditions Manufacturers can choose to engineer greater stiffness in their products by design and material selection Slider window performance can also be improved w
387. s er cen aston er co arc Glazing System Options x Base Glazing System 1 3mm Clear_Air_Clear i When simulating each of the following glazing systems will be used to create a separate simulation with the same frame geometry 2 3 mm Clear_Argon_Clear 33 mm Low e_Air_Clear 4 3 mm Low e_Argon_Clear Name the Therm files based on Glazing system name Glazing system ID Example LT_0n1 thm Figure 9 44 Glazing System Options for Lite thm THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 9 49 9 5 Problem 4 Door 9 SAMPLE PROBLEMS Table 9 27 shows the resulting U factors for the door cross section Table 9 27 THERM results for the door cross sections O e eae Far Cross Section BTU hr ft F Door Core N A N A Panel Edge N A N A Panel Core N A N A Door Lite Sill Option 1 0 5760 Door Lite Sill Option 2 0 5392 Door Lite Sill Option 4 0 4001 Door Lite Head Option 1 0 5760 Door Lite Head Option 2 0 5391 Door Lite Head Option 3 0 4628 Door Lite Head Option 4 0 4000 Door Lite Jamb Option 1 5760 Door Lite Jamb Option 2 0 5392 Door Lite Jamb Option 3 0 1629 Door Lite Jamb Option 4 0 4001 9 50 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 9 SAMPLE PROBLEMS 9 5 Problem 4 Door The following table shows the dimensions of the frame and edge portions of each cross section These dimensions will be used later to determine total product U factors Table 9 28 Fram
388. s a 2 D thermal equivalent of the cross section with and without the thermal bridging material Material with Keff 0 55 W mK Figure 8 81 Final THERM model with boundary conditions defined THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 83 8 SPECIAL CASES 8 8 Non Continuous Thermal Bridge Elements 8 8 6 Example 2 Thermally slotted cross section 0 3400 0 520 0 3400 Fb 0 009525 m 0 1016 m 0 094 Fn 1 Fb 1 0 094 0 906 Percent of thermal bridge Fb 100 0 094 100 9 4 Because the thermal bridge is 9 4 of the length of the facade the skip and debridge needs to be calculated using the isothermal plane procedure Note The rest of the example will be in SI units only with no IP unit translation Kb 160 W m K conductivity of skipped debridge in this case Aluminum THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 84 8 SPECIAL CASES 8 8 Non Continuous Thermal Bridge Elements Rt Depth conductivity Da ka 0 0086 m 0 024W m K 0 35833 m K W where Depth is length of thermal bridge in a direction of heat flow and the air is assumed to have the conductivity of 0 024 W m K Kn total depth Rt 0 0086m 0 35833 W m K 0 024W m K Keff Fb Kb Fn Kn 0 094 160 W m K 0 906 0 024W m K 15 062 W m K To convert to IP Keff 15 062 W m K 0 57782 8 703 Btu hr ft F or in alternative IP units Keff 15 062 0 57782 12 in ft 104 436 Btu in hr
389. s a setting to Automatically increment mesh parameter If this option is checked the program will increase the mesh parameter until the problem meshes If this doesn t work Simplify any unnecessarily complicated details Keep in mind that the circled point often lies on the boundary between two polygons the detail that is causing the problem could be anywhere in those two polygons and is often not at the place that is circled One method to try is to break the problem polygon into multiple polygons while keeping the geometry otherwise unchanged Another option is to delete unnecessary points such as in curves because each point generates a mesh node 6 6 2 Error Estimator THERM has a built in error estimator and automatically refines the mesh in the areas where it is needed The details of the error estimation algorithm are found in Appendix C of the THERM User s Manual The error estimator returns the Percent Error Energy Norm which is related to the gradient of heat flux energy If the 6 38 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 6 MODELING FRAME AND EDGE HEAT TRANSFER WITH THERM 6 6 Calculating Results returned value is greater than the target value THERM refines the mesh in areas with a high rate of change in the heat flux The default value for the Maximum Error Energy norm in THERM is 10 as shown in Figure 6 32 This setting forces THERM to do the error estimator calculation and return a value for t
390. s are only modeled if the distance between the exterior sides of the divider and the inside surface of the glazing system are less than or equal to 3 mm Therefore even for contoured internal dividers a simplifying assumption is made that the 5 mm rule is not applied The space between the divider edge and the glass are modeled as frame cavities and the boundary of that cavity extends to the top and bottom of the divider component See the following examples for detailed descriptions Modeling Steps The modeling steps are the following In WINDOW No new work is required because the same glazing system that is used to model the rest of the product is used in the divider model In THERM The new ISO 15099 modeling assumptions would theoretically warrant modeling horizontal and vertical dividers separately However a conservative simplification is to model all dividers including horizontal ones as vertical dividers Therefore only one divider model is created in THERM and referenced in WINDOW Set the Cross Section Type to Vertical Divider for all dividers Insert the glazing system twice once facing up with a spacer height defined as the same height as the divider height and once facing down with the spacer height set to zero NOTE Because all dividers are modeled as Vertical Dividers the CR model is not run in THERM for these files However WINDOW will still calculate a whole product CR value when these dividers
391. s in the glazing system are NFRC approved The exception is that laminates and applied films gles imported from the Optics6 User database will not have a See Section 8 for Print more details Export Figure 5 5 The List View of the Glazing System Library shows all the glazing systems 5 6 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 5 MODELING CENTER OF GLAZING WITH WINDOW 5 3 Glazing System Library Center of Glazing U factor 5 3 1 Environmental Conditions When defining the glazing system for use in an NFRC certified simulation the NFRC 100 2010 choice must be used for the Environmental Conditions Env Cnd parameter which contains the parameters defined by NFRC 100 Figure 5 4 shows the NFRC 100 2001 choice in the WINDOW Environmental Conditions Library Table 5 1 lists the values for the U factor calculation and Table 5 2 lists the values for the Solar Heat Gain Coefficient calculation H w63 Environmental Conditions Library C Users Public LBNL WINDOWE6 w6 mdb File Edit Libraries Record Tools View Help E mael OHF U tactor U factor SHGC SHGC SHGC Tin Tout Tin Tout Solar B wl Atri E C E NFRC 100 2010 Winter 15 0 21 0 18 0 0 MFAC 100 2010 Summer 320 24 0 320 Fas CEN 0 0 25 0 30 0 500 m Advanced 4 records found Import Export Report Frint Figure 5 6 WINDOW Environmental Conditions Library List View Figure 5 7 WINDOW Environmental Conditions Library Detailed
392. s many user databases as you like one at a time with Optics To create a new empty user database Click on the Database menu and select the choice Create new user database THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 124 8 SPECIAL CASES 8 11 Creating a Laminate in Optics for NFRC SS View Tools Graph Help Ctrl F Create new user database Figure 8 114 Use the Database Create new user database option to create a blank user database The program will ask you for a database name and location Name the database as appropriate and put it in whatever directory is desired the default directory for the default Optics User Database called UserGlazing mdb is the c Program Files LBNL LBNL Shared directory but any user database can be put in any directory as long as the path is specified Tools menu Save new user database as Save jn LBNL Shared d E 2 Sbitterice 7N 1GDB Update 14 4 mdb Wh IGDE Update 14 3 mdb My Recent S version 14 2 Final LAH IGOE Update 14 5 mdb Documents version 14 3 Final LAI IGDE Update mdb version 14 3 For testing l UserGlazing mdb version 14 4 For testing 2h W5 1GDB14 3Update mdb Desktop _ wesion 14 5 for checking El copy of ISDE Update mdb 7 Empty UserGlazing mdb 2 Glazing 14 0 mdb 2 Glazing 14 2 mdb lal Glazing 14 3 mdb lal Glazing 14 4 mdb 2 Glazing 14 5 mdb ll Glazing mdb My Network File name RobinOpticsD atabse mdb
393. s on the Approved Applied Films list The new film will be added to the side you select in the Apply Film to section of the dialog box You will be prompted to enter a new name for the glazing If you want to keep the new layer save it to the user database see Saving Layers to the User Database THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 134 8 SPECIAL CASES File Edit Database View Tools AE E lela Graph Glazing System Laminate ai Layer i ay ey 8 12 Creating an Applied Film Layer in Optics for NFRC Certification l0 x Help Main Database IGDB Add Glazing Edit Glazing System view All Schematic System Type z a Filename GleSys Nominal mm z lar T zolar Ab WA emn aes T n PA R eee Rf Ha Ties aon sperra sensn evenman ri iit ys Pap ne Grr photopic Fb C C C ma Fores SELIELLLELLEEELEEEELEELADELAcehneeecng cgituenisitininecieuineecneriiit tILiEILinIDiLiiebELibiiLisieehebeeeeennehit Otte iihboneehbeeLibLiibcniuirnicnit 12 UinPiiniuiriuitiiniaineauniuieiieiiibiinhisnegini eit icEhiie ELE UTES nninnininraniiii ial N A General Electric Company M E mitE WA d 1 CLR 6 CIG l Float Glass WS_NFRC_2003 AH GDB version 15 0 Spectral Properties Filename CLR 6 C1G solar T 0 786 solar Af 0 071 solar Ab 0 071 photopic T o 890 photopic Ff joos photopic Ab
394. s perpendicular to the plane of the fenestration product However fenestration products are complex three dimensional assemblies in which materials and cross sections change in a relatively short space For example metal spacers at the edge of an insulating glass unit have much higher heat flow than the center of the insulating glazing which causes increased heat loss along the outer edge of the glazing The relative impact of these edge effects becomes more important as the insulating value of the rest of the assembly increases 3 3 4 4 Frames and Sashes The heat loss through a fenestration product frame can be quite significant in a typical 1 2 by 0 9 m 4 by 3 double hung wood frame product the frame and sash can occupy approximately 30 percent of the product area In a frame with a cross section made of one uniform solid material the U factor is based on the conduction of heat through the material However hollow frames and composite frames with various reinforcing or cladding materials are more complex Here conduction through materials must be combined with convection of the air next to the glazing and radiant exchange between the various surfaces Furthermore frames rarely follow the same cross section around a fenestration product For example a horizontal slider has seven different frame cross sections each with its own rate of heat flow 3 3 4 5 Overall U factor Since the U factors are different for the gla
395. s tested with insulating material under the sill THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 6 15 6 4 Importing Glazing Systems 6 MODELING FRAME AND EDGE HEAT TRANSFER WITH THERM 6 4 Importing Glazing Systems When the frame cross section has been drawn and rotated into a vertical orientation if necessary the next step is to import a glazing system Section 5 9 Inserting a Glazing System in the THERM User s Manual contains detailed information about this step The discussion in this manual is added information about glazing systems 6 4 1 Overview For NFRC simulations a glazing system shall be imported into THERM from the Glazing System Library in the WINDOW program When THERM imports the glazing system from the WINDOW library it obtains the following information from the glazing system emittance of the glazing surfaces the effective conductivity of the glazing cavity the interior and exterior boundary conditions of the glazing system As discussed in Section 6 5 glazing systems should always be imported into the cross section in a vertical either up or down orientation it may be necessary to rotate the cross section in order to do this The figure below shows where the Locator should be positioned based on the orientation of the glazing system when it is imported The orientation of the glazing system determines in part the gravity vector orientation so it is extremely important to model it correctly NOTE
396. saeetee 9 1 Dlg CDC TN LOW oraatuan es E A nal oats E EN AE A ub E E TEA 9 1 92 Proplem 1 Vinyl Fixed VW ING OW apesse Aouad aoe eines 9 2 D2 ole DES TO Mies seuss de au cles taueh a a E Mea dstiesisae aetasauation 9 2 922 Glaz ne MaN asion sniunlanstabiraceassntsesinuasanss 9 2 9 2 3 Center of glazing Modeling WINDOW sseeseeeesseseseerseserssreeresses 9 3 9 2 4 Edge of glazing and Frame Modeling for U Factor THERM 9 4 9 2 9 Total Product U Fac Olmen a aR 9 9 9 2 6 Individual Product SHGC and VT wne SGC OSE Tand VO Se hergeni REN 9 11 9 2 7 Drawings Vinyl Fixed Window coseson 9 14 9 3 Problem 2 Aluminum Horizontal Slider Window s es 9 16 2 le Desci pon enen ceca ss eelledeneaneiuciaanesd eae tees aed tieaeetcciaatouen 9 16 9 3 2 Gla zine Mai aiaa a a E E 9 17 9 3 3 Center of glazing Modeling WINDOW ssessseseereererererrereres 9 17 9 3 4 Edge of glazing and Frame Modeling THERM 9 18 933 LOtal Product U FactOl ssania a 9 27 9 3 6 Individual Product SHGC and VT usme SHGC UQ Tand VTO G Lootin 9 28 9 3 7 Drawings for Aluminum Horizontal Slider eee eeeeeeeeee 9 30 THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 Contents 94 Problem 3 Flush Nout ony Ne Nisi E RAR 9 35 OA Nex VOCS CTD OT soci alata latest E leis 9 35 DAD GNAZIN Ma pien ti nti dieuipeues sauce siiuasiade hii seadnatiniaantedes 9 35 9 4 3 Center of glazing Modeling WINDOW ee eeeeeseeeeeeeeeees 9 36 9 4 4 Edge of glazing and Fram
397. se two conditions is by jiggling the points moving the points away from the adjacent polygon then moving them back within the sticky distance and letting the program snap them to the polygon Another way is to delete the offending polygon and use the Fill Void toolbar button to create it again which means that THERM will automatically align all points and ensure that no voids are created THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 6 37 6 6 Calculating Results 6 MODELING FRAME AND EDGE HEAT TRANSFER WITH THERM THERM can also find invalid polygons caused by points collapsing on each other creating a zero area extension In this case both the point at the tip of the extension and the extra point at its base must be deleted Turning off the Material Color and the Boundary Conditions from the View menu can sometimes help to find the problems THERM will simulate a problem even if bad points have been marked and intentionally left in the cross section because in some cases details are drawn that give bad points but which need to be modeled If changes are made to polygons on the boundary of the cross section the boundary conditions must be generated again If all the corrections are on internal polygons the boundary conditions will not be automatically deleted However in this case it is still a good idea to press the Boundary Conditions toolbar button again to ensure that all points on all surfaces have boundary segments
398. sed Report ID Name Mode Thick Flip Tsol FAsoll Asol2 Tvis Avis Avis2 Tir E1 E2 Cond Glass1 gt gt 103 CLEAR_6 DAT 60 L jo771 0 070 0 070 0884 0 080 0 080 0000 0 840 0 840 1 000 Gap 1 gt gt 1 Air 120 O Glass2 gt 103 CLEAR_6 DAT 60 O 0 771 0 070 0 070 0884 0 080 0080 0 000 0 840 0 840 1 000 Click on the double arrow to Center of Glass Result4 T j ies access the Glass emperature Data Optical Data Angular Data Color Properties Library to select Ufactor SHGC Rel Ht Gain Gap 1 Keff a laye r Wm2 K W m2 Wm K a The values in the Results section will be 2 until the glazing Select Cancel Find f ibo 4073 records found system is calculated using the Calc button Select ID Name ProductName Manufacturer Source Mode Color Thickness Tsol Reoll R mm 100 BRONZE_3 DAT Generic Bronze Glass Generic IGDB 11 4 3 124 0 646 0 062 0 101 BRONZE_6 DAT Generic Bronze Glass Generic IGDB v11 4 5740 0486 0 053 0 102 CLEAR_3 DAT Generic Clear Glass Generic IGDB v11 4 3049 O834 0 075 0 CLEAR_6 DAT Generic Clear Glass 104 GRAY_3 DAT Generic Grey Glass Generic IGDBv11 4 3 124 0 609 0 060 0 200 Sil g25LE_3ww bsf Silver 4G 25 Low E Saint Gobain Solar Gard LLC IGDB v16 3 E 3 023 0 156 0 546 0 4 DES O El Figure 5 3 Selecting glass layers in the Glazing Systems Library 5 4 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 5 MODELING CENTER OF GLA
399. sed on Ucenter 1 932 wym2 K the 1500 mm window height ca 49 Detail ayers 2 sc 0788 rather than the default 1000 Area 1 271 m2 SHGC 0 686 mm height in the Glazing Edge area 0 305 m2 Vic 074 System Library Figure 7 3 WINDOW Glazing System Library THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 7 3 7 4 Overall Product U factor SHGC VT and CR Calculations 7 TOTAL PRODUCT CALCULATIONS USING WINDOW 7 4 Overall Product U factor SHGC VT and CR Calculations When the THERM results have been imported into the WINDOW Frame and Divider Libraries and the needed glazing systems have been defined in the Glazing System Library also needed for the THERM simulations the whole product values for U factor SHGC VT and CR can be calculated in the Window Library Calculating these values is explained briefly below and in more detail in the WINDOW User Manual In the Window Library Detail View set the appropriate values on the left hand side of the screen which depend on the type of fenestration product The Mode field should be set to NFRC and the Type field should be set to the appropriate choice for the fenestration product being modeled The complete list of choices can be viewed by clicking on the double arrow next to the Type pulldown list All the choices are the official NFRC sizes except for the last three which are all custom sizes which are not allowed in NFRC simulations The Environmental Conditions field
400. side Film U Factor Surface tag None Radiation Model AutoEnclosure U Factor Surface tag Edge BC 3 mm Generic U factor Inside Film Radiation Model AutoEnclosure U Factor Surface tag None BC Interior Wood Vinyl Frame convection only Radiation Model AutoEnclosure U Factor Surface tag Frame x U factor delta T Length Wi me KE C mm Rotation Frame 4 7955 39 0 43 0001 20 0 Projected in Glass Plane SHGC Exterior 5 1 479 39 0 48 5853 20 0 Projected in Glass Plane Edge 2 5527 39 0 63 5 20 0 Projected in Glass Plane Eror Energy Morn fore Export Figure 9 35 THERM cross section and U factor results for the head cross section 9 38 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 9 SAMPLE PROBLEMS 9 4 Problem 3 Flush Mount Skylight Sill BC Adiabatic U Factor Surface tag None BC NFRC 100 2010 Exterior Radiation Model Blackbody U Factor Surface tag None BC NFRC 100 2010 Exterior Radiation Model Blackbody U Factor Surface tag SHGC Exterior BC 3 mm Generic U factor Inside Film Radiation Model AutoEnclosure U Factor Surface tag None BC 3 mm Generic U factor Inside Film Radiation Model AutoEnclosure U Factor Surface tag Edge Gravity Yector lka BC Interior Wood Vinyl Frame convection only Radiation Model AutoEnclosure U Factor Surface tag Frame Skylight Sill Modeling Assumptions Cross
401. sistance Validation Project Detailed Computer Simulations Using Finite Element Methods PP 508 515 ASHRAE Transactions Vol 102 Part 2 Zienkiewicz O C and Taylor R L 1989 The Finite Element Method 4th ed Vol 1 McGraw Hill Maidenhead UK Zienkiewicz O C and Zhu J Z 1992a The Superconvergent Patch Recovery and A Posteriori Error Estimates Part 1 The Recovery Technique International Journal for Numerical Methods in Engineering Vol 33 pp 1331 1364 Zienkiewicz O C and Zhu J Z 1992b The superconvergent patch recovery and a posteriori error estimates Part 2 The error estimates and adaptivity International Journal for Numerical Methods in Engineering Vol 33 pp 1365 1382 B 2 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual
402. so the Actual Glazing Height CR cavity height in THERM would be 1990 mm Table 6 2 Default Values for Actual Glazing Height Modeling for Condensation Resistance Real Product Height Default Glazing Height for Condensation Modeling input as the CR cavity height in THERM 2000 mm 1900 mm 1500 mm non vertical slider 1400 mm 1200 mm 1100 mm 50 Activating the Condensation Resistance model in THERM will cause boundary conditions to be drawn inside the glazing system cavity as shown in the figure below When this model is simulated THERM will automatically calculate both the U factor results and CR temperature data that will be be used when this profile is imported into WINDOW to generate the overall Condensation Resistance value for the whole product During the simulation two simulations will appear at the bottom of the screen the first for the U factor results and the second for the CR results 1500 mm vertical slider 675 mm per sash The Condensation Resistance model is not used for vertical cross sections such as a Jamb a Vertical meeting rail or a Vertical Divider Even if the CR model is activated i e the Use CR Model for Window Glazing System is checked for these Cross Section Types THERM will not perform the CR simulation for that file 6 24 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 6 MODELING FRAME AND EDGE HEAT TRANSFER WITH THERM 6 4 Importing Glazing Systems THERM generates tempe
403. soumwa fis e ST A E E A E IOl x Wh7S Swt 0 8 SE ee ee i es ee ee 2 oii as Reale Transmission ReHectance Font Reflectance back Wavelength frmicrons Double click on the selected film or highlight the film and click the OK button Ok Cancel Existing Glazing New Glazing Filename ELR Filename LRG Product Mame Fost Glass o Product Marne Float Glass ADPearance Cer Appearance Cer NFRIC ID o o O NFRCID poa Glazing Type Monolithic Glazing Type Monolithic Material Gass Material Gas Substrate Filename INA Substrate Filename WA Film Hame ble Film Hame WETS Thickness mm e0 Manufacturer Cadin Film applied to Front of Glazing Exterior T Back of Glazing Interior Thickness mm 660 Manufacturer Cardinal IG Apply tilm to Front of Glazing Exterior Back of Glazing Interior Replace existing film Create glazing with two filma Ok Cancel Click the OK button Figure 8 126 Apply the film to the substrate THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 137 8 SPECIAL CASES 8 12 Creating an Applied Film Layer in Optics for NFRC Certification The dialog appears saying a new name must be applied to the new glazing glass layer Opties tt wt CSI The current glazing will become the substrate of the new glazing You have to supply a name For the new glazing eS tt i New Fil
404. space air filled and Sungate100 Low E The figure below shows the WINDOW Glazing System Library for this glazing system se W6 Glazing System Library C Program Files LBNL WINDOW63 inyl mdb joj x File Edit Libraries Record Tools wiew Help DH ee Sml Mnaona eni OF 7 Glazing System Library List Cale F9 Defi Name 3mmiowE OO Hew Layers a 5 Tilt a 4 IG Height 1000 mm Copy Environmental FRC 100 2010 m IG Width 1000 mm Delete Comment oO OE Overall thickness j1e 500 mm Mode jt ID Name Mode Thick Flip Tol Asoll Asal Twis Avis Avice Tir E Be Cond Glass 17 ee 5009 CLESR_3 PPG 30 0627 0 076 0 077 0 898 0 086 0 086 0 000 0 840 0 840 1 000 Gapi 1 Air 125 O Glass 2 ee 5142 S100CL_3 FPG 30 0574 0262 0207 0827 0047 0062 0000 0 096 0 840 1 000 Save EOR Ca i Lcw _ meee sou LEen Report Ufactor SC SHGC Rel Ht Gain Wim E Wim 0 6987 0 6075 454 For Help press Fl Mode NFR SI MLM E Figure 9 1 WINDOW Glazing System Library for the vinyl window The results for the center of glazing U factor are shown in the following table Table 9 1 Center of glazing U factor results from WINDOW Center of Glazing U Factor Glazing Options 19 05 mm 0 75 overall thickness W m C Btu hr ft F Clear 3 mm Air Low E 3 mm 1 7886 0 3150 This glazing system will be used in THERM to calculate the edge of glazing and frame U factors and also i
405. ss replaced with wood which is the same thickness as the IG unit and then a second time with the bottom glass replaced with wood which is the same thickness as the IG unit The wood shall extend to the original sightline b If this is for a window wall or sloped glazing then the standard sill and head members are modeled 3 A physical thermal testing laboratory shall test a sample with the same cross sections as simulated in the steps listed above per NFRC 102 4 Validation is checked by comparing the values obtained by simulating the product using steps 1 and 2 above and the physical test results 8 9 1 Curtain Walls Window Walls and Sloped Glazing NERC defines a curtain wall and window wall as any building wall carrying no super imposed vertical load A curtain window wall system will typically be exterior to the building framework and will typically bypass the building floors NFRC 100 Table 4 3 states that curtain walls window walls and sloped glazed wall systems are simulated as two lites with one vertical mullion See the introduction to this section for the specific members of curtain walls window walls and sloped glazed wall systems that are to be modeled If the intermediate vertical and horizontal members were simulated full width or height for the jambs head and sill then the total area of the frame as simulated would be significantly larger than actual frames so for rating purposes some members depending on THERM
406. stem defined in Glazing System Library THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 193 8 SPECIAL CASES 8 15 Frits These steps are illustrated in more detail in the following discussion 8 15 2 Frit Example The following example is for a simulated sandblast frit from the CGDB 1 Shading Layer Library Import the frit product from the CGDB into the Shading Layer Library In the Shading Layer Library List View click the Import button and browse to the CGCB database whose default location will be in C Users Public LBNL LBNL Shared Shading Layer Library C Usersrdmitchell Documents My Dropbox sntre Tramings6 Ta A FAC Training for Software Approval Complex ID Product ame p Venetian 40 Venetian 445 Venetian 490 Import Venetian BO Venetian B45 Format Window 5 or 6 Database Venetian B30 Import database plic LENLSLENL Sharedyiv63 CGDB6 1 2 mdb Browse Venetan CO Jatan C45 r Avoid creating duplicate records in export database by searching for identical records ee Venetian C30 Venetian COO Cancel Venetian DO Venetian D45 Venetian O90 White Frit Clear Frit no pigment Slim White YB Closed Slim White Venetian Blind Slim White Open Slim white Venetian Blind Figure 8 180 Browse to the CGDB database to import the frit records into the Shading Layer Library When the CGDB dialog box appears highlight the records to import and click the Select button or click the Select All butt
407. sults U factor 2 9194 Wim2 K Click on a component to display characteristics below SHGC and T detail Mo Generic Generic Dividers Dividers Dividers H A 0 75000 1 50000 SHGC 0 4728 aa a gt POD inches yt 0 3485 Click on the Detail crf 2 etal button to show the a 2a ale E E SHGC1 0 78405 0 70284 0 62632 SHGCo SHGC VTo VT values for By the product vm 0 00000 0 00000 0 00000 0 77090 0 68694 0 60782 For Help press F1 Mode NFRC SI Num x Geen Figure 9 24 Window Library record for the best glazing option for the aluminum horizontal slider 9 28 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 9 SAMPLE PROBLEMS 9 3 Problem 2 Aluminum Horizontal Slider Window Table 9 13 SHGCo SHGC1 VTo and VT data for the best glazing option in this product line Clear Argon Low E Dividers E lt 1 25 4 mm Dividers modeled at gt 1 25 4 mm No Dividers 0 75 modeled at 1 5 SHGCo 0 01315 00590 01590 0 01850 SHGC 0 78405 0 70284 0 62632 C a Ce SHGC Calculation Using Equation 4 1 from NFRC 200 Using Equation 4 1 from NFRC 200 and the data from Table 9 13 calculate the whole product SHGC from the SHGCo SHGCi and SHGCc SHGC SHGCo SHGCc SHGC SHGCo Without Dividers SHGC 0 01315 0 5971 0 78405 0 01315 0 4735 With Dividers lt 1 25 4mm modeled at 0 75 SHGC 0 01590 0 5971 0 70
408. suming the substrates for each film all came from the same glass batch and 20 spectral data files one for each film on the substrate resulting in 21 files submitted Reference substrate Replied layers Film Applied film Spectral data is Spectral data is With these two sets of data That applied film measured for a measured for the Optics can back out the then appears as construction made up clear glass used optical properties of the a record in the of the applied film as the substrate applied film Applied Film glued to clear glass layer in the type in Optics the substrate layer previous applied and can be used film as an applied measurement film on other substrates in Optics Each of the 20 spectral data files for the films applied to the substrate would reference the substrate spectral data file Additionally the glass manufacturer will not have to submit spectral data for the applied films attached to 6 mm clear or 6 mm gray cases as they can be simulated in Optics from the applied film on the 3 mm clear substrate 8 12 3 Using this Procedure for NFRC 200 NERC 200 specifies a procedure for calculating SHGC and VT for attachments which applies to Applied Films This procedure specifies that reference glazing systems shall be calculated with and without the film installed from the following glass layers Single 3 mm clear Single 6 mm clear Single 6 mm gray The first case Single 3 m
409. sure the Laminate tab is selected Choose menu option File New Laminate You will be prompted to save the current laminate if one already exists Note if you created new layers and did not save the layers or did not save the laminate which would save any new layers the new layers will be lost when you start a new laminate 8 11 3 2 Wavelength Sets Use the NFRC default wavelength set which is called Optics This setting is shown on startup of the program and also can be viewed and changed if necessary from the menu option Tools Select Wavelength Set 8 11 3 3 Add Layers to a Laminate You can add monolithic coated and interlayer type layers to a laminate There are a number of rules for building laminates 1 The first and last layer in a laminate must be a non interlayer type e g monolithic or coated 2 Youcan place as many interlayers as you like adjacent to each other but you must separate rigid non interlayers with at least one interlayer 3 For NFRC certified simulations you can NOT place a coating next to an interlayer If you break rule 1 or 2 the operation will be cancelled Use the Add Interlayer tab above the database to add interlayers To add other layers use the Add Glazing tab Only those database records with enough data to be loaded into a laminate will be shown in these views if you want to see all records in the database including those which cannot be used in laminates use th
410. system Figure 8 138 Head cross section with fully retracted venetian blind inside a double glazed system THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 152 8 SPECIAL CASES 8 14 Venetian Blinds Between Glass Integral Top of venetian blind assembly Block of Aluminum Alloy used to represent the geometry and material properties of the stack of venetian blind slats in their fully retracted position In this case the stack of blind slats is approximately 15 mm wide and 50 mm long This frame cavity starts where the throat is 5 mm and then is modeled as a frame cavity Bottom of venetian blind assembly The space between the stack of venetian blind Glazing system cavity slats and the glazing layers Note that some cavities are linked to the glazing system and some are not according to the rules in Section 6 4 4 Figure 8 139 The Head cross section with the retracted venetian blind including the stacked slats and the top and bottom assemblies for the blind that are continuous across the section Follow these steps to model a fully retracted venetian blind Note This example was done for Aluminum slat blinds If the material of the blinds is not Aluminum use the appropriate material properties from NERC 101 Procedure for Determining Thermo Physical Properties of Materials for Use in NFRC Approved Software Programs for the stack of retracted venetian blind slats 1 Draw the Head cross section
411. ta T Length Wi ori K mm Rotation C Frame 4 8084 39 0 43 0002 30 0 Projected in Glass Plane SHGC Exterior 5 1 345 39 0 48 5853 30 0 Projected in Glass Plane Edge 2 5455 39 0 63 5 30 0 Projected in Glass Plane E t Error Energy Norm TEI por a Figure 9 37 THERM cross section and U factor results for the jamb cross section 9 40 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 9 SAMPLE PROBLEMS 9 4 Problem 3 Flush Mount Skylight 9 4 5 Total Product U Factor In WINDOW import the THERM cross sections into the Frame Library 15 x Window Library C Program Files LBNL WINDOW63 Sky light mdb File Edit feu telalla Frame Library C Program Files LBN LW N D OWES kulight mdb Help 4 gt n Bae di oF Libraries Record Tools view Detailed View Frame Uvalue Wwe re k 4795 3 553 4 608 3 545 4 760 3 551 Edge Edge Blazing Prd Uvalue Correlation Thickness Wm mm mm H A 16 9 HA 16 9 H A 16 9 Update Type Source 1 HO THM 2 JB THM SL THM Therm Head Therm Jamb Therm Sill Copy Delete 4 Advanced 3 records found Import Esport Report Print Mode NFRC i NUM E For Help press F1 Figure 9 38 WINDOW Frame Library ss Window Library C Program Files LBNL WINDOW63 Skylight mdb File Edit Libraries Record Tools Yiew Help Oe sale List Hi Calc F9 New Copy Delete Save
412. tabase and determine whether or not you should overwrite those records with records you are going to import into that database THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 7 15 7 5 Project Databases 7 TOTAL PRODUCT CALCULATIONS USING WINDOW Window Library C gt U sers Public LBNL YW DO OWE wi mdb Detailed View Cale ID Name Type Width Height Ufactor SHGC Tvis CR mm mm wir me K Winyl 3 mm low E No Dividers Fixed picture 1200 1500 200 0604 0648 4390 b 2 Vinyl 3 mm low E With Dividers Fixed picture 1200 0561 430 f Copy Delete tlk Click the export button to bring up the Export dialog box Advanced 2 records found Import Epor Report E sport f Selected record s Print Allrecords Set Format to WINDOW 5 RRN Fdo E Database z Database and click New to make a new database Export C Users Public LENLAWINDOW6Mest2 mdl Browse New 4 m Avoid creating duplicate records in export database by searching for identical records OK Cancel H Save As Save in Ji WINDOW6 e ef Ee Name Date modified Type aa 2b w6 mdb 5 17 2013 6 27 PM Microsoft Access u E 7b w6 Pre Version 6 3 62 original mdb 5 14 2013 12 48 PM Microsoft Access ll w6 Pre Version 6 3 54 original mdb 5 14 2013 12 48 PM Microsoft Access Ah w6 GlzSysAirSpaceTest mdb 5 14 2013 12 48 PM Microsoft Access n 4h woVenetian mdb 5 14 2013 12 47 PM Microsoft Acc
413. tems Library The Center of Glass Results tab at the bottom of the screen shows the results for the glazing system The U factor results are based on a default glazing system height of one meter This center of glazing U factor value will be recalculated in the Window Library to reflect the true height of the product being modeled See Section 7 Total Product Calculations for more information THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 5 5 5 3 Glazing System Library Center of Glazing U factor 5 MODELING CENTER OF GLAZING WITH WINDOW All the Glazing System Library records can be seen in the List View access by clicking the List button from the Glazing System Library Detailed View H W6 3 Glazing System Library C Users Public LBNL WINDOW6 w6 mdb File Edit Libraries Record Tools View Help Environmental Overall Conditions Keff Thickness Uval sL Wire k mm wr mz K NFRC 100 2010 18 50 asia ormo 0783 NFRIC 100 2010 0 809 0 786 NFFIC 100 2010 0 538 0 698 NFRC 100 2010 0 878 0814 NFRC 100 2010 0 709 0 703 NFRC 100 2010 0574 0 720 NFRIC 100 2010 0 788 074 NFRC 100 2010 0 788 0741 NFRC 100 2010 0 718 0 085 T vis Double Clear Air Double Low e Air Double Clear with Argan Triple Clear 3mm Low e air 3mm Clear Sample Gle5ys Oo Po Po Pa to Po Po Po 2 3 4 z B z J 9 records found Sample GlzSys w Int Blue YE Import A in the Mode field indicates that all the glass layer
414. tend to blend well with other architectural colors Many other specialty colors are available for particular aesthetic purposes Tinted glass is made by altering the chemical formulation of the glass with special additives Its color changes with the thickness of the glass and the addition of coatings applied after manufacture Every change in color or combination of different glass types affects transmittance solar heat gain coefficient reflectivity and other properties Glass manufacturers list these properties for every color thickness and assembly of glass type they produce Tinted glazings are specially formulated to maximize their absorption across some or all of the solar spectrum and are often referred to as heat absorbing All of the absorbed solar energy is initially transformed into heat within the glass thus raising the glass temperature Depending upon climatic conditions up to 50 percent of the heat absorbed in a single layer of tinted glass may then be transferred via radiation and convection to the inside Thus there may be only a modest reduction in overall solar heat gain compared to other glazings There are two categories of tinted glazing the traditional tints that diminish light as well as heat gain and spectrally selective tints that reduce heat gain but allow more light to be transmitted to the interior The traditional tinted glazing often forces a trade off between visible light and solar gain For these bronze an
415. that has been simulated so the values for Nusselt Nu Heat Flow Direction Temperature and Emissivity for Side 1 and Side 2 are not the default values but have been automatically calculated by the program NOTE The Attributes button is used only for the NFRC CMAST program Select the Frame Cavity NFRC 100 choice z from the Material Library pulldown list xl Because the Cavity Model for that material gt Material Pr A A is set to ISO 15099 the heat flow direction emissivities and temperatureswill be automatically calculated OF es ween ans ID 463 Attributes Keff 0 1063 wink OESS Horizontal dimension 26 421 mm The emissivity values are associated with the m Cancel Library Attributes The Nusselt number Nu is calculated before the simulation based on default temperatures but will be recalculated based on the actual cavity temperatures during the simulation materials adjacent to the cavities and they Vertical dimension 27 772 mn are automatically calculated by the program ihe lo The Heat Flow Direction is during the simulation If there are materials automaccalv calcilated b adjacent to the cavity which have different ears a an ene emissivities the program will area weight the Heat Flow Direction Left prog not necessary to check it for every cavity before the simulation final values as in this example Side Temperature 5 1 og E
416. the Libraries Import button in the Del menu Greate Link Gas Librar dialo Pure ee ts y g Conductivity Coefficients Remove Link Rename box 0 0028730 0000775 A E 0 00007 76 E 0 0000000 Viscosity Coefficients 0 000003 STP Properties Save Lib As aU Load Lib Step 4 Select the WINDOW gas record from the g 0 000000 pulldown list and click on the c 0 0000000 Import button Specific Heat Coefficients 2 r 369995 E 0 0123240 C Step 3 Use the Browse 0 000000 button to select the Molecular Weight WINDOW database 24 0 Windows Gas Import x ID Name Gas ERAR e Mix Gas type 2 Gas Mix coe Window Database C Program Files SLE A LSWIN DOB Browse IY Protected Y 4 a bey 3 102 2 917 idx dy 0 862 2 075 llen 2247 Step 0 394 inches E Edit Gas Fill properties sill NUM ot Figure 8 20 Import the gas mixture entries into the THERM Gas Library THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 19 8 SPECIAL CASES 8 3 Dividers 3 Make anew frame cavity material in the THERM Material Library based on Frame Cavity NFRC 100 but with the Gas Fill field set to the correct gas mixture from the Gas Library Frame Cavity NFRC 100 Material Type C Sold f Frame Bavi C Glazing Cavity ft Enema Radiation Endasue sold Eiaperties Conducte i Etuate Emtesisity ps Cavity Properties Load Lib Radiation Model
417. the Draw Locator Step 2 Repeat mode Shift F2 p ppr menu or press Shift F2 To position the Locator click on the lower left Flip hand corner of the space Pi o where the glazing system Clear Bad Points will be placed 25 4 mm 1 inch DE of x y 140 8 216 9 idx dy 109 2 39 2 len 116 1 Step 10 0 mm ot Sets Locator for copying and importing Glazing Systems sill NLM ot Figure 8 61 Position the locator so that the first glazing section can be inserted THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 61 8 SPECIAL CASES 2 Insert the glazing system for the Sill with the following settings THERM 6 3 SL NoGlazing THM P l Orientation Up Cavity height 1000 mm Sight line to bottom of glass measure this value with the tape measure or get from dimensioned drawings 8 5 Skylights Spacer height measure this value with the tape measure or get from dimensioned drawings Edge of Glass Dimension 63 5 mm 2 5 inches Draw spacer not checked oe File Edit View Draw Libraries Options Calculation Window Help pereu Veh amp t Set Material Set Boundary Gondition FS Material Library Shift F4 1 ies Glazi Boundary Condition Library ShiFt FS o to Libraries azing Gas Library Shift F Systems Select Material Boundary Condition Glazing Systems UFactor Mames Glazing Systems j x ID Hame Glazing System 2 Skylight Double Glz H Layers ao Ucenter 3 23 Thi
418. the Solar Heat Gain Coefficient SHGC and Visible Transmittance VT for products is outlined in NFRC 200 using values of SHGCo SHGCi VTo and VTi These values are calculated in WINDOW for the best glazing option modeled with the highest frame and edge U factor frame as outlined in NFRC 200 Section 4 2 3 A Since only Glazing Option 1 was modeled for this example we will assume that it is the best glazing option for the purpose of determining SHGC and VT values Using this procedure display the results for the SHGCo SHGC VTo and VT for the best glazing option Clear Air Low E by clicking on the Detail button on the Window Library Detailed View screen as shown in the figure below The SHGC and VT detail dialog box will show the SHGC and VT values for the following three cases for this glazing option No Dividers Dividers lt 25 4 mm modeled as 19 5 mm Dividers gt 25 4 mm modeled as 38 1 mm ss Window Library C Program Files LBNL WINDOW63 Aluminum Slider mdb File Edit Libraries Record Tools view Help O x Cae d sO SiBlin gt Baen OF Z 2 New Copy Delete Save Report Tan Dividers Display mode 4 Lit Dei o Calc F9 Name Aluminurm 3mm CIG Mode NFRC X Type Horizontal Slider gt gt Width 1500 mm Height 1200 mm Area 1 800 m2 Tit 90 Environmental Conditions NFRC 100 2010 Normal Total Window Re
419. the actual divider geometry is modeled in THERM the THERM file is imported into the WINDOW Divider Library and used in a record different from those used for the SHGCo SHGC1 VTo VTi calculations in the Window Library This is shown in the following figures H W6 3 Window Library C Users Public LBNL WINDOW6 w6 mdb File Edit Libraries Record Tools View Help Ha eti OF 2 k Window Library C gt U sers Public LBN LAW N DOW 66 mdb Detailed View Width Height UFactor SHGC This CR mm Wi me E mim Vinyl 3 mm low E No Dividers Fixed picture E 0 604 4al 490 E Winyl 3 mm low E With Dividers Fixed picture 1200 1500 1 935 0 526 0 561 49 0 t Window Library record defined for the U factor Adhereae calculation for a product that is manufacturered with dividers The generic dividers are NOT used in this case 2 records found Import Export Report Print For Help press F1 Mode NFRC SI Figure 7 9 Window Library List View for the U factor with Dividers case The Window Library Detailed View shows that the divider used for this product is from a THERM file rather than one of the generic dividers fA w63 Window Library C Users Public LBNL WINDOW6 w6 mdb File Edit Libraries Record Tools View Help bage Heald Pw Bae Mii OFZ List ID 2 X Calc F9 Name 3 mm low E With Divide Mode NFRC X New T Type Fixed picture vl gt gt Copy i Width 1200 mm T Select De
420. the aluminum spacer with a metal that is less conductive e g Stainless steel and change the cross sectional shape of the spacer Another approach is to replace the metal with a design that uses materials that are better insulating The most commonly used design incorporates spacer sealer and desiccant in a single tape element The tape includes a solid extruded thermoplastic compound that contains a blend of desiccant materials and incorporates a thin fluted metal shim of aluminum or stainless steel Another approach uses an insulating silicone foam spacer that incorporates a desiccant and has a high strength adhesive at its edges to bond to glass The foam is backed with a secondary sealant Both extruded vinyl and pultruded fiberglass spacers have also been used in place of metal designs There are several hybrid designs that incorporate thermal breaks in metal spacers or use one or more of the elements described above Some of these are specifically designed to accommodate three and four layer glazings or IGUs incorporating stretched plastic films All are designed to interrupt the heat transfer pathway at the glazing edge between two or more glazing layers 2 14 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 2 FENESTRATION PRODUCTS 2 7 Thermally Improved Edge Spacers Warm edge spacers have become increasingly important as manufacturers switch from conventional double glazing to higher performance glazing For purposes of determining
421. the frame portion of the meeting rail cross section including both sash elements and the sweeps between them The interior surface of extrusions which are generally unpainted metal should have an emissivity of 0 2 Define the air between the sashes as Frame Cavity NFRC 100 Sash 2 Sash 1 Emissivity of interior surfaces of unpainted extrusion 0 2 Sweep Figure 8 2 Frame portion of meeting rail cross section 2 Position the Locator using the Draw Locator menu choice or pressing Shift F2 in the lower left corner of the frame where the first glazing system will be inserted as shown in Figure 8 3 Step 2 Position the Locator using Shift F2 or the Draw Locator menu choice in the lower left corner of the frame where the glazing system will be inserted Figure 8 3 Position the Locator for the first glazing system THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 3 8 SPECIAL CASES 8 2 Meeting Rails 3 Using the Libraries Glazing Systems menu option or the F6 key insert the upper glazing system as shown in Figure 8 4 In this example the spacer will be copied and pasted into the cross section later Add a spacer and use the Material Link Library Create Link to link the glazing system cavity conductivity with adjacent cavities in a spacer which is open to the glazing system cavity if necessary THERM 6 3 Untitled 2 laj x File Edit View Draw Libraries Options Calculation Window Help 18 x
422. the glass layer from the Add Glazing tab Double click on the layer in the database or Using the mouse drag the layer from the database over the layer button where you want to add the layer and release the mouse button or Select the layer in the database then choose the menu option Database Add Replace Layer or Select the layer in the database then right click to display the pop up menu then choose Add Replace Layer If you are replacing a layer a dialog box will appear to confirm that you want to replace the existing layer Note Select a layer in the database by clicking on it with the mouse or by browsing to it by pressing the up and down arrow THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 120 8 SPECIAL CASES 8 11 Creating a Laminate in Optics for NFRC 8 11 3 5 Add Interlayers To add an interlayer to a laminate Select the first available unoccupied layer by clicking on a layer button Select the Add Interlayer tab Select the interlayer you want to add and load it into the laminate see 8 11 3 3 Add Layers to a Laminate Select the desired interlayer for the laminate Click on the Add construction double click the mouse and that Select the Layer Interlayer tab interlayer will be added as the next layer in the Button for the laminate Interlayer Glazing System Laminate gt Add Glazing Add Interlayer add Embedded Coating Edit Lhrinate view all Schematic Layer
423. the length is being calculated The figure below illustrates this This incorrect frame length will cause the U factor over the projected length to be calculated incorrectly The U factors results dialog box has a feature which allows a custom frame length to be entered in order for THERM to calculate the correct U factor This situation happens in some skylight files although it potentially could happen in any model The figure below describes the steps required to use the Custom Frame Length feature For multiple glazing options setting the custom frame length for each option can be quite cumbersome One technique is to set the custom frame length in the base file first and then the program will pick up for custom length values for each multiple glazing option lt lt Adiabatic Boundary Condition THERM calculates this as the projected Y frame length in this example it is 32 16 mm This is the true projected Frame Length in this example it is 15 651 mm Figure 6 37 Example of a case where THERM does not calculate the projected Y frame length correctly because of an adiabatic boundary condition that overlaps an interior boundary condition 6 44 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 6 MODELING FRAME AND EDGE HEAT TRANSFER WITH THERM 6 6 Calculating Results E The projected Y frame U factor delta T Length wim2 K E mm Rotation length calculated Edge 1 6950 41 3 63 4898 N A Projected Y x incorrectly
424. the overall fenestration product U factor the edge spacer has an effect that extends beyond the physical size of the spacer to a band about 63 5 mm 2 5 inches wide The contribution of this 63 5 mm 2 5 inch wide glass edge to the total fenestration product U factor depends on the size of the product Glass edge effects are more important for smaller fenestration products which have a proportionately larger glass edge area For a typical residential size window 0 8 by 1 2 meters 3 by 4 feet changing from a standard aluminum edge to a good quality warm edge will reduce the overall fenestration product U factor by 0 01 to 0 02 Btu hr ft F THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 2 15 2 7 Thermally Improved Edge Spacers 2 FENESTRATION PRODUCTS 2 16 June 2013 THERME6 3 WINDOW6 3 NFRC Simulation Manual 3 FENESTRATION HEAT TRANSFER BASICS 3 1 Overview Much of the information in this chapter is taken from the book Residential Windows A Guide to New Technologies and Energy Performance by John Carmody Stephen Selkowitz and Lisa Heschong Additional information can also be found in the ASHRAE 2001 Handbook of Fundamentals 3 2 Energy Flow Mechanisms Overall energy flow through a fenestration product is a function of Temperature Driven Heat Transfer When there is a temperature difference between inside and outside heat is lost or gained through the fenestration product frame and glazing by the combined e
425. ther cavities Cavities around the Venetian blind that touch the glazing system cavities imported from WINDOW can be linked to the glazing system cavity following the 5 mm rule described in Section 6 4 4 In the example below the frame cavities that have a throat adjacent to the glazing cavity greater than 5 mm are linked to the glazing cavity and those that are less than or equal to 5 mm are modeled as frame cavities THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 148 8 SPECIAL CASES 8 14 Venetian Blinds Between Glass Integral 5 mm This cavity has a throat gt 5 mm where it touches the glazing system cavity so it is not linked to the glazing cavity but is modeled as a separate frame cavity This frame cavity starts where the throat is 5 mm and then is modeled as a frame cavity his cavity has a throat gt 5 mm where it touches the glazing system cavity so it is linked to the glazing system cavity These cavities are gt 5mm where they touch the glazing system cavity so they are all linked to the glazing system cavity LZ Figure 8 135 Determine which cavities around the Venetian blind can be linked to the Glazing System Cavity THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 149 8 SPECIAL CASES 8 14 Venetian Blinds Between Glass Integral 8 14 3 Open Venetian Blind There are two scenarios for Open venetian blinds e Retractable Open Venetian blinds that retra
426. ties may be completely enclosed or partially ventilated only on the outdoor side depending on the configuration and size of the section connecting the frame cavity with the outdoor environment Upon the completion of the numerical simulation the error estimator portion of the program makes local error estimates and based on the error levels refines troublesome regions of the model and recalculates the entire model This procedure is repeated until no local regions show error levels higher than what is prescribed This error estimator is based on the error energy norm methodology by Zinkiewitz see the THERM 2 0 User s Manual Section 9 References The details of the models are in the THERM 2 0 Users Manual THERM 2 0 for Analyzing Two Dimensional Heat Transfer Through Building Products and Conrad 5 and Viewer 5 Technical and Programming Documentation Curcija 2006 The following diagram shows the program flow AA Sune 2013 THERM6 3 WINDOWG6 3 NFRC Simulation Manual 4 SUMMARY OF ALGORITHMS 4 3 THERM Computational Methods Figure 4 2 shows the steps involved in a THERM analysis Model is defined See Finlayson 1998 z Geometry is drawn m Material properties assigned 7 Boundary Conditions assigned Mesher generates mesh See George 1991 and Baehmann 1987 Finite Element Analysis Solver calculates temperature and heat flux values Mesh is refined if EEN value is not met See Curcija 1995 Curcija 1998 Pe
427. ting fenestration products for retrofitting applications 2 6 Improved Glazing Products There are three fundamental approaches to improving the energy performance of glazing products 1 Alter the glazing material itself by changing its chemical composition or physical characteristics An example of this is tinted glazing The glazing material can also be altered by creating a laminated glazing 2 Apply a coating to the glazing material surface Reflective coatings and films were developed to reduce heat gain and glare and more recently low emittance and spectrally selective coatings have been developed to improve both heating and cooling season performance X Assemble various layers of glazing and control the properties of the spaces between the layers These strategies include the use of two or more panes or films low conductance gas fills between the layers and thermally improved edge spacers Two or more of these approaches may be combined Each of these improvements to the glazing is discussed below 2 6 1 Tinted Glazing Both plastic and glass materials are available in a large number of tints The tints absorb a portion of the light and solar heat Tinting changes the color of the fenestration product Tinted glazings retain their transparency from the inside so that the outward view is unobstructed The most common colors are neutral gray bronze and blue green which do not greatly alter the perceived color of the view and
428. tion Manual June 2013 8 146 8 SPECIAL CASES 8 14 Venetian Blinds Between Glass Integral 8 14 2 Modeling Rules Definitions WINDOW Glazing System Library Dtop Dbot Dleft Dright In the Glazing System Library the values for Dtop Dbot Dleft and Dright represent the space between the edge of the shading system including hardware and the top bottom left or right of the glazing system cavity These values are used to define the convection that will occur between the shading system and the glazing system These values are used for the glazing system thermal calculations in WINDOW and also to place interior and exterior shading systems in THERM Frame to Shading System distance for Interior Shading Systems Frame Dtop Dbot Dleft Dright Glass gt A Shading System Frame to Shading System distance for Between Frame to Shading System distance Exterior Glass Shading Systems Shading Systems Figure 8 134 Determine the distance from the frame spacer and the shading system at the top bottom left and right of the window THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 147 8 SPECIAL CASES 8 14 Venetian Blinds Between Glass Integral THERM Sightline The Venetian blind hardware can define the sightline rather than the frame depending on the geometry of both the frame and the Venetian blind The sightline is used in the Tvis and SHGC calculations Linking Glazing System Cavities to o
429. tion of the Meeting Rail section will be modeled with the same venetian blind considerations as the Head section The other cross sections Jambs Sills and Meeting Stiles are modeled normally without any venetian blind considerations In WINDOW 1 Glazing System Library Create the appropriate glazing system in the Glazing System Library In this case it is not necessary to model a venetian blind in WINDOW because the blind is fully retracted In THERM 1 Frame Geometry Draw the frame geometry including Head Sill Jamb and Meeting Rail if appropriate 2 Glazing System Import the glazing system defined in WINDOW no venetian blind modeling needed into the frame geometry Make sure that the Sight line to bottom of glass value includes the height of the block representing the closed venetian blind so that the Frame and Edge of Glass boundary conditions and U factor tags are defined automatically by THERM 3 Boundary Conditions Define the Boundary Conditions in the normal manner no venetian blind was modeled in WINDOW so the Boundary Conditions in THERM do not need to be modified for a Shading System THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 151 8 SPECIAL CASES 8 14 Venetian Blinds Between Glass Integral Use the proper modeling technique where the frame meets the surround panel ie model these voids as air cavities Pt ei 4 _ Stack of venetian blind slats lt Double glazed
430. tions epecitied Would you like to Oo K it Create the glazing option files and perform all simulations Cancel Simulate the current file only Create the glazing option files but do not perform the simulations 4 bay 55 5 136 5 idx dy 24 4 120 5 len 123 0 Step 10 0 mm ZA Ready sill NUM 2 Figure 6 34 When a file w ith multiple glazing options is calculated THERM gives several calculation options THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 6 41 6 6 Calculating Results 6 MODELING FRAME AND EDGE HEAT TRANSFER WITH THERM Multiple base case files with multiple glazing options in each file can be added to the Calc Manager as shown in the figure below The Calc Manager does not ask the three simulation option questions it implements the first choice which is that to make all the files and then simulate them The Calculation Log can be viewed to see the status of the runs The information in the Calculation Log can be sorted by clicking on a column heading THERM 6 3 sample sill THM Oj x aa File Edit wiew Draw Libraries Options Calculation Window Help la x Ci co A E 4 oO ff t m Calculation Fg Show Results Display Options Shitt Fo Show U Factors Ctrl F9 Background Calc Add to queue Status Running C Program Files LBNL WINDOWEB345S amples sample sill_008 thm Close au Remove Pause Interrupt Log C Program Files LENLSYWINDOWE6355 ampl s sample sill_011
431. to best meet the overall required performance parameters Thus a simple inspection of the inner or outer surface of the frame is no longer an accurate indicator of the total material or its performance Since the sash and frame represent from 10 to 30 percent of the total area of the fenestration unit the frame properties will significantly influence the total product performance 2 4 1 Wood Frames Wood fenestration products are manufactured in all configurations from sliders to swinging windows Wood is favored in many residential applications because of its appearance and traditional place in house design A variation of the wooden product is to clad the exterior face of the frame with either vinyl or aluminum creating a permanent weather resistant surface Clad frames thus have lower maintenance requirements while retaining the attractive wood finish on the interior From a thermal point of view wood framed products perform well The thicker the wood frame the more insulation it provides Wood framed fenestration products typically exhibit low heat loss rates However metal cladding metal hardware or the metal reinforcing often used at corner joints can degrade the thermal performance of wood frames If the metal extends through the fenestration product from the cold side to the warm side of the frame it creates a thermal short circuit conducting heat more quickly through that section of the frame 2 4 2 Aluminum Frames The bigg
432. topic Af cc a ea E Figure 8 111 Select the desired interlayer from the Add Interlayer tab for layer 2 8 11 3 6 Flip Layers in a Laminate To flip layers in a laminate Select the layer to flip by clicking a layer button Choose the menu option Edit Flip Layer or Right click on the layer button to display the pop up menu and select Flip Layer THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 121 8 SPECIAL CASES 8 11 Creating a Laminate in Optics for NFRC If flipping the layer would place a coating adjacent to an interlayer and this will break the laminate building rules see 8 11 3 3 Add Layers to a Laminate and the laminate cannot be constructed for NFRC certification Note Check the schematic view and the layer spectral averages if you are not sure which way a layer is oriented If any glass layers are flipped make sure to add an F to the NFRC ID in the name of the final laminate 8 11 3 7 View the Properties of a Laminate To view the calculated spectral data spectral averages and other properties of a laminate Select the laminate by clicking on the Lamin layer button The laminate is now the current layer so its spectral data and spectral averages are displayed in the lower part of the screen Click on the Lamin Button and Optics will calculate and display the calculated properties of the laminate construction in the column below that button i Optics Sele
433. tor Surface tag of Frame BC Adiabatic U factor Tag None 4 BC Interior lt frame type gt Convection only Radiation Model AutoEnclosure U factor Tag Frame x BC lt glazing system name gt U factor Inside Film Radiation Model AutoEnclosure U factor Tag Frame p BC lt glazing system name gt U factor Inside Film Radiation Model AutoEnclosure U factor Tag Edge BC NFRC 100 2001 Exterior U factor Tag SHGC Exterior BC NFRC 100 2001 Exterior U factor Tag None BC lt glazing system name gt U factor Inside Film Radiation Model AutoEnclosure U factor Tag None tt BC Adiabatic U factor Tag None Figure 8 147 Define the boundary conditions for the cross section 7 Calculate the results for this cross section 8 Complete the calculations for the other product cross sections Sill Jambs and Meeting Rails Stiles as appropriate 9 Import all the cross sections into the WINDOW Frame Library and calculate the total product U value SHGC and VT THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 162 8 SPECIAL CASES 8 14 Venetian Blinds Between Glass Integral 8 14 1 3 Non Retractable Open Venetian Blind Inside a Double Glazed System Non Retractable Open Venetian Blind are systems that are fixed at the bottom do not retract up and the open position is defined as the blind slats set to a horizontal position perpendicular to the plane of the
434. tory These laminates are not stored in a central NFRC database The naming convention for the laminate should describe the layers used to construct the laminate using the IGDB Layer ID for glass layers and the interlayer name from the Optics program for the interlayer If a glass layer is flipped add the F designator to the end of the layer number The total number of characters not including extension but including separators in the name cannot exceed 45 lt glass layer ID gt lt F if layer is flipped gt lt interlayer name from Optics gt lt glass layer ID gt lt F if layer is flipped gt For example 102 030keepsafe 2026F THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 117 8 SPECIAL CASES 8 11 Creating a Laminate in Optics for NFRC 8 11 2 Laminate Interlayer Data Optics can accurately calculate the optical properties of laminates as long as the component layers with the following characteristics and only interlayers submitted with these characteristics will be included in the Approved Interlayer List for NFRC certification Interlayers are measured with transparent glass with a solar transmittance Tsol gt 0 820 and Tvis gt 0 890 This ensures that a constructed laminate in Optics will always have a similar or lower transmittance than the reference laminate which determines the interlayer properties No glass layers have coatings next to interlayers embedded coatings Subs
435. trate layers the base glass to which the interlayers are applied are measured separately from the interlayers This is the responsibility of the manufacturer submitting data to the IGDB as discussed below As discussed in the LBNL document which contains guidelines for submitting data to the IGDB International Glazing Database Data File Format Version 1 4 April 2003 an interlayer is an adhesive layer used to join components in a laminate The optical properties of laminate layers cannot be measured directly Instead they are calculated from the spectral properties of a reference laminate which consists of the interlayer laminated between two glass layers of known optical properties To submit data for an interlayer both the spectral optical properties of the reference laminate and the glass layers used in the reference laminate should be submitted This means that in order for an interlayer to be added to the Optics Interlayer type and therefore used in making laminate constructions in Optics the spectral data for a reference laminate which contains that interlayer is submitted to the IGDB as follows Reference laminate substrate layers Interlayer Interlayer Spectral data is Spectral data is With these two sets of data The interlayer measured for a measured for the Optics can back out the appears in laminate construction clear glass used optical properties of the Optics as an made up of the as the s
436. truct glazing systems For NFRC simulations the NFRC approved glass layers from the International Glazing Database shall be used WINDOW will install a current International Glazing Database but the library is updated frequently so check the website mentioned in Section 5 1 for updates The data in the International Glazing Database is determined according to the NFRC 300 procedure When the NFRC approved glass data is used a symbol appears in the Mode fields of both the Glass Library shown in Figure 5 2 and the Glazing System Library shown in Figure 5 1 All certification simulations must use the most current NFRC approved International Glazing Database IGDB The Glass Library imported from the International Glazing Database contains glass products of specific manufacturers as well as several entries for generic uncoated products indicated by the Manufacturer field being set to Generic The values for these generic entries are not measured properties from any specific glass products but are averaged spectral data from at least two samples See Section 8 for instructions about how to create laminates and applied films in the Optics program and import them into the WINDOW Glass Library File Edit Libraries Record Tools a va F Glass Library C Users Public LBNL SWINDOWw6 w6 mdb View Help T Detailed View Advanced 4073 records found Import Export Report Print Update IGDB ID Name BRONZE_3
437. ts boeeasereesameeBobreai aren mtneaniat 8 73 Boundary Conditions for Steel Skin Doors ee eee eeseeseeeeseeeseeeseeeeseeees 8 73 Of TOP ACCES sedate E A 8 74 eZ alc OO VCIV IEW sass accu iiectsienactedaunsesuties a wibdeaiend 8 74 8 7 2 Linking Glazing Cavity properties imported from WINDOW for Open opaCETS EMT re Tree er On orem eT Tere erere none ery at 8 75 8 8 Non Continuous Thermal Bridge Element cece eeeeeeseceseeeeeeeeneeeeeeeeees 8 77 092 WIOCENNS SLEDS circa tie eet eta cheater adalat taints Aaa ea 8 77 OAs EGUA NONS aas a cued ans anne ee nl aaa 8 79 THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 Contents 8 8 5 Example 1 Bolts in Curtain Wall gcccnecceceelraeh eel deiieeas 8 80 8 8 6 Example 2 Thermally slotted cross section ceeseeseeseeeeeeeees 8 83 8 8 7 Example 3 SKip antd de brid 6 Coca aieecvsieziscciusd sands ree ta geelateencamuiiontedves 8 87 8 9 Site Built fenestration products Curtain Walls Window Walls and Sloped GIIZINE engasa a E Mean deine iaddcoeculysRientid seb T vies 8 90 8 9 1 Curtain Walls Window Walls and Sloped Glazing 8 90 8 9 2 Curtain Wall Modeling Procedure eee eseeeeeeeneceseeeseeenneeees 8 92 6 10 Garage Roline DOGS repann a a aai 8 104 8 10 1 Sectional Garage Door Insulated and Non Insulated 8 104 S102 ROMS DO GP ornon a a e TN 8 111 8 11 Creating a Laminate in Optics for NERC eeeeesesseseesesseeerssresrersersrssr
438. two layers separated by an air space of varying thickness ranging from no separation at the edges to as much as 3 inches 7 6 cm at the top of the bubble The average separation is used to calculate the effective U factor Multicell polycarbonate sheets which can be mounted with the divider webs running vertically or horizontally are available The divider webs increase the effective insulating value of the glazing by reducing convection exchange within the cells especially when they are mounted horizontally 2 6 8 Multiple Panes or Films By adding a second pane the insulating value of the fenestration product glass alone is doubled the U factor is reduced by half As expected adding a third or fourth pane of glass further increases the insulating value of the fenestration product but with diminishing effect Triple and quadruple glazed fenestration products became commercially available in the 1980s as a response to the desire for more energy efficient products There is a trade off with this approach however As each additional layer of glass adds to the insulating value of the assembly it also reduces the visible light transmission and the solar heat gain coefficient thereby reducing the fenestration product s value for providing solar gains or daylighting In addition other complications are encountered Additional panes of glass increase the weight of the unit which makes mounting and handling more difficult and transportation mor
439. ual 9 SAMPLE PROBLEMS 9 5 Problem 4 Door 9 5 5 Total Product U Factor SHGC and VT Total product U factor SHGC and VT values for door products cannot be calculated in the same manner as window and skylight products Because WINDOW cannot area weight the opaque portions of the door models and cannot read the results from THERM files with tags other than Frame Edge or None total product values must be manually calculated outside of WINDOW by inputting the center of glazing results from WINDOW and the frame and edge results from THERM into a spreadsheet The spreadsheet calculation is outside the scope of this manual and is therefore not included in this example However NFRC has Benchmark Spreadsheets for area weighting wood steel skin and fiberglass skin entry doors which is available on the NFRC website www nfrc org Instruction on the use of that spreadsheet is not included in this manual 9 5 6 Wood Stile and Rail Door Drawings The following pages contain detailed drawings for this door THERM6 3 WINDOWG6 3 NFRC Simulation Manual June 2013 9 61 9 5 Problem 4 Door 9 SAMPLE PROBLEMS Half Panel with Glass Layout 3 0 27 DAYLIGHT 4 500 35 3 4 DAYLIGHT 36 13 16 4 500 7 500 S Bo ee ee 23 DAYLIGHT 4 500 4 500 i Figure 9 54 Half Panel with Glass Layout 9 62 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 9 SAMPLE PROBLEMS 9 5 Problem 4 Door Half P
440. ubstrate interlayer That interlayer Interlayer type interlayer layers in the then appears as a record in and can be used sandwiched between previous the Interlayer type in to make other two identical pieces laminate Optics and can be used as laminates of clear glass the measurement an interlayer in other substrate layers laminates constructed in Optics Figure 8 107 How Optics deconstructs measured data to obtain interlayer information Optics can do an accurate calculation for the interlayer properties from the reference laminate as long as the substrate glass layers have a high solar and visible transmittance hence the requirement of Tsol gt 0 820 and Tvis gt 0 890 This ensures that laminates that are later created in Optics with this interlayer will almost always have a lower solar and visible transmittance then the reference laminate THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 118 8 SPECIAL CASES 8 11 Creating a Laminate in Optics for NFRC 8 11 3 Constructing a Laminate in Optics 8 11 3 1 Building a New Laminate When Optics starts you can start building a laminate immediately by switching to the Laminate tab and adding layers see 8 11 3 3 Add Layers to a Laminate Layer m Filename iz lz zz Figure 8 108 Click on the Laminate tab to start constructing a laminate If you have created a laminate already but want to start over with an empty laminate Make
441. uch a poor insulating value allows heat to flow out of a space almost unimpeded If the temperature inside is 21 C 70 F and outside is 18 C 0 F the glass surface of a single glazed product would be about 8 C 17 F cold enough to form frost on the inside of the glass 3 3 2 Convection Convection affects the heat transfer in many places in the assembly the inside glazing surface the outside glazing surface inside frame cavities and inside any air spaces between glazings A cold interior glazing surface cools the air adjacent to it This denser cold air then falls to the floor starting a convection current which is typically perceived as a draft caused by leaky fenestration products One remedy for this situation is to install a product with lower heat loss rates that provides a warmer glass surface On the exterior a component of the heat transfer rate of a fenestration product is the air film against the glazing surface As wind blows across the product causing convection and the insulating value of this air film diminishes which contributes to a higher rate of heat loss Finally when there is an air space between layers of glazing convection currents can facilitate heat transfer through this air layer By adjusting the space between the panes of glass as well as choosing a gas fill that insulates better than air double glazed fenestration products can be designed to minimize this effect 3 3 3 Radiation All obje
442. uding hardware and the top or left right bottom of the glazing system THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 167 8 SPECIAL CASES 8 14 Venetian Blinds Between Glass Integral Glazing System Library ID 24 Name LowE DbIGlz intB Opern Non Retract Layers 3 B Tilt 90 IG Height 1000 01 ror Environmental ae Conditions MFRE 100 2010 IG width 1000 00 men Comment Overall thickness 46 892 mm Mode E ID Name Mode Thick Flp El E2 Cond Dtop mm D bot mm Oright ram Cleft mmn Glass 1 9801 CLEAR3 LOF 30 CIf 0840 0 840 1 000 Gapi 1 ir 7 5 LI Shade 2 FR 3002 Slim White Open 14 8 C 0900 0 900 160 000 0 0 Gap 2 1 Air 42 O Glass 3 ee 9921 LOW E_3 LOF 30 LJ 0156 o840 1 000 Set values for Dtop Dbot Dleft Dright based on the geometry of the blind product Rel Ht Gain Ket Gap 1 Keff Gap 2 Kett Wire Wi fm Val fn K Wi fmm E 510 0 1207 0 1732 0 0198 Figure 8 153 Define a Dtop Dbot Dleft and Dright in the Glazing System Library THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 168 8 SPECIAL CASES 8 14 Venetian Blinds Between Glass Integral In THERM 1 Frame Geometry Draw the frame geometry including Head Sill Jamb and Meeting Rail if appropriate 2 Glazing System Import the glazing system defined with the venetian blind horizontal slats into the frame geometry For this example the Head cross section the following settings we
443. ugh VT does not directly affect heating and cooling energy use it is used in the evaluation of energy efficient fenestration products and therefore is discussed following the solar heat gain section The origin of solar heat gain is the direct and diffuse radiation coming directly from the sun and the sky or reflected from the ground and other surfaces Some radiation is directly transmitted through the glazing to the space and some may be absorbed in the glazing and then indirectly admitted to the space Sunlight is composed of electromagnetic radiation of many wavelengths ranging from short wave invisible ultraviolet to the visible spectrum to the longer invisible near infrared waves About half of the sun s energy is visible light the remainder is largely infrared with a small amount of ultraviolet This characteristic of sunlight makes it possible to selectively admit or reject different portions of the solar spectrum While reducing solar radiation through fenestration products is a benefit in some climates and during some seasons maximizing solar heat gain can be a significant energy benefit under winter conditions These often conflicting directives can make selection of the best product a challenging task See Section 2 6 9 for a more detailed discussion of these properties of fenestration products Reflection Transmission Absorption Figure 3 2 A glazing system s properties of reflection transmission and absorption d
444. uilding Technologies Department Environmental Energy Technologies Division Lawrence Berkeley National Laboratory Berkeley California 94720 http windows bl gov software software html John Carmody College of Architecture and Landscape Architecture University of Minnesota Minneapolis Minnesota Charlie Huizenga Center for Environmental Design Research University of California Berkeley California Original Publication Date January 2011 Revised December 201 1 Revised June 2013 Regents of the University of California This work was supported by the Assistant Secretary for Energy Efficiency and Renewable Energy Office of Building Technology Building Technologies Program of the U S Department of Energy under Contract No DE AC03 76SFOO0098 Contents Ve INTRODUCTION rriren ee eee eens 1 1 eis SO MOTV NOW pania n a a tates lussivaneianccsoctiseutesinsae le miotae inet nnsaheratanian 1 1 2 PFENES TRATION PRODUC S siiicnpsiiaeu niori aeniei 2 1 ZN SIV CIM NOW oeg na N A AAA A 2 1 2 2 Fenestration Product Sash Ope ratiONincisinen a beau ade 2 1 22A Projected Or Hinged Windows seiret imatran a a a R 2 2 LP 22 EIT VW MIGIO N Sae nan a a mnsietnata ieee 2 2 Zos Odne Glass DOO eronneen lat tonsutseaeheransciay 2 2 2 2 4 French Doors and Folding Patio Doors sessseeesereeeeeererereres 2 2 22 0 Skyliehntsand Roof WINdOW Soei dosseccicuadeuels decade ieersearamvecsiae 2 2 2 3 Performance Implications of Basic Fenestrat
445. ulated in THERM WINDOW algorithms are documented in publications which can be found on the LBNL WINDOW 6 Documentation website http windows lbl gov software window 6 w6_docs htm WINDOW 5 Program Description A PC Program for Analyzing the Thermal Performance of Fenestration Products R Mitchell C Kohler D Arasteh John Carmody C Huizenga Dragan Curcija LBNL 44789 DRAFT June 2001 TARCOG Mathematical Models and Computer Algorithms for Calculation of Thermal Performance of Glazing Systems with or without Shading Devices Conrad 5 amp Viewer 5 Technical and Programming Documentation Calculation of Optical Properties for a Venetian Blind Type of Shading Device Optical Model of Fritted Glazing in WINDOW A New Method for predicting the Solar Heat Gain of Complex Fenestration Systems I Overview and Derivation of the Matrix Layer Calculation A New Method for predicting the Solar Heat Gain of Complex Fenestration Systems II Detailed Description of the Matrix Layer Calculation 4 1 2 THERM The THERM program calculates Frame and edge of glazing properties the results of which are imported into WINDOW where the total product properties are calculated 4 2 WINDOW Computational Method Heat transfer across a fenestration product is a function of both the temperature difference between the inside and outside and the incident solar radiation on the product In order to evaluate heat transfer through a
446. und Import Export Step 5 The selected records will be imported into the library Report Print Figure 8 18 Import the THERM file into the WINDOW Divider Library 10 Use the new divider in the calculation of the complete product values in the main screen of WINDOW THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 17 8 SPECIAL CASES 8 3 1 3 Gas Filled Glazing Systems 8 3 Dividers If the glazing system being modeled with a divider is gas filled it is necessary to model the divider with the same gas fill as the glazing system This means a new material must be defined for the gas filled frame cavities around and inside the divider The THERM Gas Library contains entries for standard gases as well as examples of gas mixtures These gases are not made in THERM they are made in the WINDOW Gas Library and then imported into the THERM Gas Library When the gas mixtures have been imported into THERM they can be referenced from a new frame cavity material for the divider model as shown below 1 Create the gas mixture in the WINDOW Gas Library Presumably it already exists for the product glazing system model See Section 4 6 Gas Library in the WINDOW User s Manual for details about creating new entries in the Gas Library W6 Gas Library C Program Files LBNL WISDOW63 4w6 mdb File Edit Libraries Record Tools View Help hoe amp e Sle Bas Library C Program FilesSLENLVWIN DOW ESE
447. ure 8 1 shows an example of the meeting rail from a horizontal aluminum slider Creating the cross section for a meeting rail is no different than any other model in THERM A few things to keep in mind are Two glazing systems are imported one facing up and one facing down 1 Interior boundary conditions for each of the glazing systems are labeled with the Edge U factor tag and the program averages the values for both to derive one Edge U factor 2 Model the meeting rail with the glazing systems facing up and down see Section 6 3 2 Cross Section Orientation in this manual If the DXF file is drawn with them in a horizontal position draw the frame cross section and then rotate it before inserting the glazing system The following discussion lists the steps for making a cross section with two glazing systems and assigning the correct boundary conditions Exterior Interior Edge of glass Sightline The Sightline determines the Edge of glass delimeter for the Boundary Conditions Frame Edge of glass Figure 8 1 Meeting rail cross section THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 2 8 SPECIAL CASES 8 2 Meeting Rails 8 2 2 Steps for Meeting Rail U factor Calculation 1 Using dimensioned drawings or a DXF file create the cross section for the frame portion of the meeting rail In Figure 8 2 the frame for the horizontal aluminum slider meeting rail has been created Sweep Step 1 Draw
448. urtain Wall Mullion Cross Section mull thm THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 93 8 SPECIAL CASES 8 9 Site Built fenestration products Curtain Walls Window Walls and Sloped Glazing Modeling the Intermediate Vertical Mullion Using the dimensioned drawings or a DXF file create the cross section for the frame portion of the vertical mullion The figure below shows a THERM cross section of the frame portion of the vertical mullion Make sure that the section is oriented correctly with the glazing oriented up and down If bolts are present make sure to model them as non continuous thermal bridging elements if needed see Section 8 9 Pay particular attention to the aluminum finish in order to assign the correct materials to the drawing In the figure below where the arrows point to Aluminum bolt Aluminum Figure 8 91 Mullion frame cross section without glass Mull_noglass thm This vertical cross section will be used for the vertical intermediate mullion and for the jambs The jamb model it is necessary to determine and mark the 12 width point between the sightlines The easiest way to do this is to make temporary reference rectangles as follows THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 94 8 SPECIAL CASES 8 9 Site Built fenestration products Curtain Walls Window Walls and Sloped Glazing Determine Frame Midpoints In order to model the half width frame dimensions for th
449. ve must be not greater than 2 5 mm ISO 15099 Standard 6 14 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 6 MODELING FRAME AND EDGE HEAT TRANSFER WITH THERM 6 3 Draw the Cross Sections 6 3 9 Modeling Sloped Sills A product with a sloped sill must be modeled in the same way that it was tested When a vertical sliding or fixed window is tested the air space underneath the sloped portion of the sill is filled with expanded polystyrene insulating material For the simulation of the sill section this window must have the insulating material modeled underneath the sloped portion of the sill as well as shown in the figure below The bottom surface of the insulating material will have an adiabatic boundary condition applied The surface of the insulating material that faces to the interior will have a boundary condition applied that is the same as the condition applied to the frame above the insulating material The U factor surface tag for the interior facing surface of the insulating material will be defined as Frame which ensures the correct projected frame dimension will be used in the area weighting of the total window U factor ai Boundary condition is the same for all edges facing in Expanded Polystyrene Insulating material The insulating material is added so that the full frame height is used by the program U factor tag Frame A BC Adiabatic U factor tag None Figure 6 14 Model the sloped sill as it wa
450. viders 3 Import the glazing system again as an additional glazing system below the first one the locator does not have to be moved but facing down this time Use the following settings for this glazing system Orientation Down Actual Cavity height 1000 mm 39 inches Sight line to bottom of glass 3 175 mm Spacer height 0 Edge of Glass Dimension 63 5 mm 2 5 inches Glazing System Height 150 mm 6 0 inches Draw spacer Not checked Insert the glazing system as an Additional Glazing THERM 6 3 Untitled 2 Insert Glazing System Insert 2 glazing system wilbi Set Sight line to Click on the Add as bottom of glass to additional glazing the appropriate system radio button in values for the the Insert Glazing simulated spacer and System dialog box Spacer height to zero Insert Glazing System Gg i oh Fiberglass PE Resin Use existing BC from library select below Use convection plus enclosure radiation v NFAC 100 2010 Exterior v Figure 8 25 Import the second glazing system as an additional glazing system facing down THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 8 24 8 SPECIAL CASES 8 3 Dividers 4 Draw or copy and paste from another THERM file the polygons in the cavity that represent the divider The figure below shows the divider for this example drawn with the material set to Aluminum Alloy THERM 6 3 Simulate
451. with the same frame geometry appear in the Glazing System Options dialog box 11 Sample Glz5ys r amm Clear Add Remove Move up Move down pen Name the Therm files based or Glazing system name f Glazing system ID E sample zample sil_008 thm Figure 6 18 Select the glazing systems to be associated with the base case file Click on the radio button which indicates to the program how to name the individual THERM files for each glazing system option Either the Glazing System ID or Name will be appended on to the base case 6 Calculate the Results the file can now be simulated or more files can be created and all the files simulated through the Calc Manager This is explained in more detail in Section 6 6 Calculating the Results 6 20 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 6 MODELING FRAME AND EDGE HEAT TRANSFER WITH THERM 6 4 Importing Glazing Systems 6 4 4 Linking Glazing Cavities When a glazing system cavity touches another cavity there are two options in terms of modeling 1 Link the glazing system cavity to the other cavity rather than modeling the second cavity as a frame cavity or 2 Model the non glazing system cavity as a frame cavity The method used to determine how to model this case depends on the geometric relationship of the glazing system cavity to the other cavity Here are the guidelines Un sealed glazing units such as storm panels and venetia
452. y Norm Daga E sport Figure 9 16 THERM cross section and U factor results for the sill fixed cross section THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 9 21 9 3 Problem 2 Aluminum Horizontal Slider Window 9 SAMPLE PROBLEMS Jamb Vent BC Adiabatic U factor tag None 4 Cross Section Type Jamb Gravity Vector Into the Screen Gravity Vector kd BC 3 mm CIG U factor Inside Film Radiation Model AutoEnclosure U factor tag None BC NFRC 100 2010 Exterior Radiation Model Blackbody U factor tag None BC 3 mm CIG U factor Inside Film Radiation Model AutoEnclosure U factor tag Edge BC Interior Thermally Broken Frame convection only Radiation Model AutoEnclosure U factor taq Frame to BC Adiabatic a U factor tag None U factor delta T Length WWT C BC NFRC 100 2010 Exterior Radiation Model Blackbody U factor tag SHGC Exterior x Rotation mm Frame 5 1970 39 0 53 2379 30 0 Projected in Glass Plane SHGC Exterior 5 6158 39 0 53 2378 o o Projected in Glass Plane Edge 2 1350 39 0 64 6568 20 0 Projected in Glass Plane E t Eror Energy Nom 3 34 por lt a a alas Figure 9 17 THERM cross section and U factor results for the jamb vent cross section 9 22 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 9 SAMPLE PROBLEMS 9 3 Problem 2 Aluminum Horizontal Slider Window Jamb Fixed BC Adiabat
453. y are given in Conrad 5 and Viewer 5 Technical and Programming Documentation Curcija 2006 48 00 2 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 4 SUMMARY OF ALGORITHMS 4 4 Total Product Calculations F Edge of Divider Center of rarae Glazing Edge Glazing Installation Clearance Frame T Edge of Glazing 63 5 mm 2 5 Center of glazing Projected Fenestration Product Area Divider Edge 63 5 mm 2 5 Divider Divider Edge 63 5 mm 2 5 Rough Opening Center of glazing Edge of Glazing 63 5 mm 2 5 Clearance Divider Frame t Installation Figure 4 3 Components for the whole product area weighted calculation The view on the left is a section and the view on the right is an elevation THERM6 3 WINDOW6 3 NFRC Simulation Manual June 2013 4 9 4 4 Total Product Calculations 4 SUMMARY OF ALGORITHMS The following figure is from NFRC 100 and shows in detail how each section of the product is area weighted The WINDOW program implements this scheme for area weighting Figure 1 Fenestration Product Schematic Vertical Elevation LEGEND C Center of glazing Edge of glazing F Frame D Divider DE Edge of divider Center of glazing edge of glazing divider edge of divider and frame areas for a typical fenestration product Edge of glazing and edge of divider areas are 63 5 mm 2 5 in wide The sum of these component
454. y height 1000 mm 39 inches Sight line to bottom of glass height of the divider in this example it is 19 05 mm 0 75 inches Spacer height height of the divider in this example it is 19 05 mm 0 75 inches Edge of Glass Dimension 63 5 mm 2 5 inches Glazing System Height 150 mm 6 0 inches Sight line to shade edge 0 not modeling shading system Draw spacer Not checked THERM 6 3 Untitled 2 B File Edit view Draw Libraries Options Calculation Window Help Di co ed IB LE Set Meter j oundary Condition F5 Insert Glazing System x Orientation Up OF Cancel Material Library Shift F4 Boundary Condition Library Shift F5 Gas Library Shift F6 Glazing system width 21 mm CR cavity height 1000 mrm Step 3 Sight line to bottom of glass 13 05 mm Set Glazing System Spacer height 19 05 mm l popes Edge of Glass Dimension 63 5 mm j Sight line to bottom of Step 1 l glass and Spacer Select Glazing Systems Baa sste veii 150 di height Divider height from the Libraries menu Sight line to shade edge 0 mm Edge of Glass Dimension 63 5 mm Step 2 2 5 Select the appropriate glazing Glazing system height system from the WINDOW library ences Ut 150 mm 6 0 Use CR Model for Window Glazing Systems Glazing Systems x e ane see ea 1 00 ID Name i Default t Custom Gap 1 onan p 2010 Exterior Keff 0 079026 wW m K Glazing System T amm Low
455. zing edge of glazing zone and frame it can be misleading to compare U factors if they are not carefully described In order to address this problem the concept of a total fenestration product U factor is utilized by the National Fenestration Rating Council NFRC A specific set of engineering assumptions and procedures must be followed to calculate the overall U factor of a fenestration unit using the NFRC method In most cases the overall U factor is higher than the U factor for the glazing alone since the glazing remains superior to the frame in insulating value The U factor of a product is calculated with the product in a vertical position A change in mounting angle can affect its U factor 3 4 June 2013 THERM6 3 WINDOW6 3 NFRC Simulation Manual 3 FENESTRATION HEAT TRANSFER BASICS 3 4 Solar Heat Gain and Visible Transmittance 3 4 Solar Heat Gain and Visible Transmittance The second major energy performance characteristic of fenestration products is the ability to control solar heat gain through the glazing Solar heat gain through fenestration products tends to be the single most significant factor in determining the air conditioning load of a residential building The intensity of heat gain from solar radiation can greatly surpass heat gain from other sources such as outdoor air temperature or humidity Visible transmittance VT is an optical property that indicates the amount of visible light transmitted through the glazing Altho

NFRC Simulation Manual - National Fenestration Rating Council

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