NavIAQ User Manual - BRE projects website
Contents
1. the number of persons per room The frame can be dragged at the top edge Manual NaVIAQ page 5 5 Bottom of the screen ETES The elapsed time for ventilation and CO2 i p esiid It turns red if persons are more than 4 arag the slider A right mouse click will hours inside 2 type a number in the box reset the CO2 concentrations wind speed wind direction y outside Temperature 7 C02 outside ia a SERES eee eee eeaay Be EW Fes T 1 iat rici 1 is re oe Tae See Ct Jae ieee tereeeeton slow fast 0 5 ms 15 0 180 360 1 0 10 C 25 320 340ppm 360 E show area stop at stop time Nip EndESCIk Vv Us zero persons ips Time to stop the Show leakage and CO2 simulation opening areas CO2 Simulation without persons Here are controls for wind speed wind direction temperature and outside CO concentration igure 6 The limits are adjustable Click and type a number Show pressures Exit the program saving the input in the Win registry The minimum and maximum is also adjustable by clicking This input is not limited and exotic results may follow at odd values In the frame Ventilation calculation the button Start starts a series of dynamical calculations of all flow rates and stops at a certain accuracy or 10 simulated seconds e Onan average PC the simulation is a few times faster than real time A second click starts calculations with a gr2. viewed towards East Left and right from the green rooms are the blue and yellow rooms of type 1 and type 2 Those may have different settings for window and door positions O closed 100 open Their input is in the frames with the same color at the right hand side of the floor plan All other input is copied from the input given for the green rooms shown as cross section in the middle of the screen The staircase is only simulated at the East side and duplicated in flows and volume to account for the West staircase Manual NaVIAQ page 3 4 Middle of the screen Click at a flow arrow and figure 3 opens s section CO2 concentration Blue outside b ms 4 7 Sere eee jou Click in a room and figure 4 opens 0 0 Red gt 1500 ppm 47 North 2 13 Pa 1738 ppm Check the input Figure 2 Expert opinion on a few aspects of the input 3 5 2 30 Pa Hal oom n50 vents 0 81 0 81 em2 L 81 Air leakage of the building expressed as the number of air changes per hour at 50 Pa the so called n50 value 5 2 5 1 i m B 47 South 2 57 Pa 971 ppm Power kW to heat the ventilation ai current 0 09 2 rooms teference 0 48 Energy by ventilation The current value is the energy to warm up the ventilation of the two rooms in the cross section The reference is to warm up 40 dm3 s This frame can be scaled by dragging the left side The 6 arrows indicat
3. Manual NatVent IAQ office ventilation program NaVIAQ V1 3 Delft 1998 October 03 TNO Bouw department BBI by hans phaff 1 Installation Here follows a short description of the installation on a PC with Windows locally installed Setup will install a number of dlls in the windows system directory if no Visual Basic 5 0 program had been installed before For systems that have Windows shared at a network drive the systems operator must install the program first to update the system dlls Close all programs also stop virus checkers that prevent writing in the Windows directories If earlier versions of NaVIAQ exist see 1 1 Removal of earlier versions of NaVIAQ Place the NatVent IAQ CD Rom or floppy disk 1 in the drive Open that drive in the Explorer On the CD Rom open the folder Design Tools NavlIAQ Installation files Double click the setup exe program NatVent IAQ Setup NatVent IAQ Setup Begin the installation by clicking the button below Welcome to the NatVent IAQ installation progam 0 menn j Setup cannot install system files or update shared files if they are in use Before proceeding we recommend that you close any applications you may be running Click this button to install NafVent IAD software to the specifi directory Click here to begin setup Directory C Program Files NatVent AQ Chanc Ext Setup e Click OK to confirm that no other programs run Click the larg
4. a N m check box to display the open area of ventilation components grilles leaks windows Air supplied by a fan and duct from outside to various rooms of the building flow rate supplied to a room System for ventilation consisting of a one or more ducts and one or more fans A natural ventilation system works without fans by means of natural wind induced pressures and or temperature driven pressure differences buoyancy Outdoor air temperature as given by meteo Computer term for an input box for text or numbers TNO is a research organisation for Applied Physics in Holland The institute Bouw means Building is involved in Building and Construction Research Energy used to warm up the ventilation air air flow rate through a building component Computer model that calculates the flow rates in a building This is often done by iterative approximation of the indoor pressures so that the mass flow rates that enter the building and rooms equal the outgoing flow rates System for ventilation consisting of one or more ducts and fans could be used A natural ventilation system works without fans by means of natural wind induced pressures or temperature driven pressure differences buoyancy Renewal of indoor air by outdoor air to dilute concentrations of aerosol pollutants like CO2 H2O odors and to supply Oo Internal volume of the building m Pressure on the facade or roof calculated from the dynamic pressure and th
5. by At dm s 1Pa and g s 1Pa the reported values may be non integer numbers as they are derived from integer cm values Press ESC to return to NaVIAQ 6 6 Edit input of the building Stop all calculations The ventilation area of a ventilation component is given here as free area That is 12 cm 1dm s at 1Pa Most data is limited within a certain range For instance e room volumes 20 200 m e air leaks up to 500 cm Manual NaVIAQ page 7 After every change of the input the whole building blower door value n50 number of air changes at 50 Pa is recalculated If there are flow controllers n50 is ill defined At lower pressure flow controller flow rates usually don t decrease 6 7 Input that is not in the cross section All non grayed fields can be edited 6 8 Clicking on an arrow ventilation component By clicking an arrow a movable input frame opens Position The most important most frequently changed data is the opening position of a window door which can be changed by the top slider in 5 positions 0 closed to 100 open 6 9 Size of the ventilation opening In the second sub frame are the ventilation areas of the components in e closed position this may be the leak e opened position The open position is not a large opening but meant as a provision for ventilation Real open windows and doors would be in the range of 10000 cm The flow exponent n is here a fixed function of the size of t
6. create sufficient over under pressure The flow rate through the fan is measured and expressed in n50 flowrate 3600 buildingvolume Ventilation of buildings driven by wind and thermal stack effect buoyancy natural ventilation NatVent NaVIAQ number of persons number of rooms pressure in the rooms pressure show area supply supply system temperature meteo text box TNO Bouw ventilation energy ventilation flow rate ventilation model ventilation system Ventilation volume wind pressure wind speed wind window Manual NaVIAQ page 11 Ventilation without systematic use of fans but mainly by means of wind pressures and thermal stack or buoyancy pressures EC program into natural ventilation giving guidance to overcome barriers NatVent Indoor Air Quality simulation program for office buildings the number of persons per room in NaVIAQ number of rooms along one side of the corridor Pressure in the office difference with outside is calculated by the ventilation model If there are large under or over pressures a warning is given If there is mechanical extract ventilation and the leak is set to its minimum and inlets are all closed then the pressure becomes unrealistically low Normal fans would not be able to create such pressures but in NaVIAQ the mechanical flow rate is independent of the pressure Air pressure difference with the outdoor pressure without wind pressure as reference expressed in P
7. d speed direction temperature and outside CO concentration The limits are also editable by clicking 6 13 Ventilation calculation The following controls also active during a calculation Manual NaVIAQ page 8 e The Check box show area displays the number of cm at all links Flow controllers also show their limiting values e The Check box room pressure controls the display of the room pressures COs Concentration calculation 6 14 CO calculation The following controls are also active during a calculation e The slider slow fast can speed up the concentration simulation e The Check box zero persons toggles the number of persons in the whole building to 0 and back to the original number thus simulating a lunch break e The text box with stop time can be used to stop the CO calculation at a predefined time hh mm An input of zero like 0 0 is interpreted as don t stop e Aright mouse click on the CO button will zero all CO concentrations If stopped the zero concentrations will be shown at the next start The CO source strength is 5E 6 m s per person 7 Compare two versions of a building NaVIAQ can only work with one building at a time You may open the program more than once From the File menu you can open a previously saved building To start the subsequent run with the current office press F1 and click Save input after that the building may be changed The next instance of
8. e NatVentlAQ icon Read further at 2 Run NatVent IAQ 1 1 Removal of earlier NatVent IAQ versions From the windows taskbar Start Settings Control panel Add Remove Programs Select NatVent IAQ in the list Click Add Remove There may be an error that the program group NatVent could not be removed Ignore this The NaVIAQ icon will stay in the Start Menu until the next boot of the PC 1 2 Old system files It is possible that the Setup program asks confirmation to replace system files Setup Ist contains a list of the dll files to be replaced It may be safe to make a copy of the original files and to run ERD EXE see Windows CDROM before installing NaVIAQ 2 Run NatVent IAQ From the windows taskbar click Start Programs look for NatVent and then NatVent IAQ in the programs list and click it Click the Start button or press the Enter key Manual NaVIAQ page 1 To start a simulation press the Start button at the ventilation frame or and afterwards the CO button For help press F1 or open the manual from the menu Help Open manual The tool tips can be switched on off with the check box in the lower left corner The name NaVIAQ means Nat Vent Indoor Air Quality NaVIAQ simulates ventilation flow rates and concentrations of human exhaled CO in one floor of an office building The program runs best at a screen resolution of 1024 768 or 800 600 16 million colors and small system characters The program alway
9. e concentrations are calculated for CO2 which is produced by the persons in the building and depend also on the outside concentration At the bottom of the cross section is a frame with the heating power This is the power for two rooms Calculated from the ventilation heating loss of the whole office building and divided by the number of rooms along one side of the corridor The heating loss of the staircase is thus added to that of the rooms Below is as reference the power to warm up 40 dm s from outside to room temperature The left edge of this frame can be dragged to be large enough for losses at low outside temperatures up to 9 kW 6 3 Help text Press F1 to show a short help text Press ESC to return to the NaVIAQ screen At the bottom of the help screen is a button to reset all input to the default input 6 4 Manual At the left below the cross section of the building is a button Manual that opens this manual NaVIAQ Manual doc if Microsoft Word is present at this PC as WINDOWS program Search via CTRL F or the menu Edit Search 6 5 Check the input Stop the calculations Press or click on the button Check the input below the cross section An overview follows with checks of the input e There may be proposed changes that can be applied automatically with the button at the bottom of this screen Apply changes This is followed by a new check of the input e Suggested changes to be applied manually are indicated
10. e cp value wind speed measured at a meteorological station Wind speed as given by meteo m s Large window used for airing
11. e the ventilation flow rates in the cross section of the building The size of the arrows is the relative size of the flow During the CO simulation the arrows are colored from blue Name of the link m supply qrille South m opening position used 100 closed S 5 selectable leakage values s for area 0 lt 520cm2 lt 20 the link in closed position E ventilation component data 7 The flow exponent is a function of i leaks gt the leakage and can t be changed by the user areafom2 nd 0 75 opening at z 100 open J Area of the ventilation component if it were in full open position 100 arealem2 500 IV controller limited flow to inside dm3 s 20 ventilation result flow dm3 s 2 0 NX Pana to outside dm3 s 4 q Figure 3 Limitation of the flow rate to inside direction of the arrow at start up and to outside Manual NaVIAQ page 4 Switch for the flow controller limiter The actual area in the simulation is the product of the here input area and the opening position percentage Results from the ventilation simulation outside concentration to red 1500 ppm A click at an arrow yields the input frame of figure 3 The mouse can drag these frames The top edge border is the best place to drag the frame You can t drag the frame by clicking on the internal elements sliders internal frames and textboxes The inp
12. eater accuracy Click Stop to end these calculations at a sufficient approximation of the equilibrium value The total elapsed real time in the building is displayed The dynamical CO simulation starts at a click at the CO button The bars show the concentration e The slider slow fast can speedup the simulation e The number of persons can be set to zero temporarily with a click in the check box zero persons e f a simulation with persons takes more than 4 hours the elapsed time will be displayed in a red label to show that normally a break would occur If the number of persons is set to zero this red is cleared again Manual NaVIAQ page 6 6 Step by step After installation click Start Programs NatVent NatVent IAQ Click OK or press Enter 6 1 First start Press F1 Click Reset all input Click OK Press ESC to return to the NaVIAQ screen Press S or click on start in the frame Ventilation calculation to start the ventilation calculation This stops at a reasonable value or after 10 s simulation in the office building Press C or click on CO in the frame concentration calculation The simulation does not stop Press an other time on C or click on CO to stop the calculation 6 2 Results The ventilation calculations are dynamical The course of flows and pressures at the indicated time approximates that in the real building The flow rate is displayed in dm s internally mass flow rates are used Th
13. he leak NaVIAQ does the following Closed A ventilation component that is closed has only its leak the area given by the top slider in the ventilation component frame in Error Reference source not found The flow rate is calculated with the displayed flow exponent mass flow rate Aiak 0 63 SQRT 2 rho SGN dp ABS dp n as shown here A is in m and the flow rate in kg s Opened As soon as the position slider is not closed and in position 20 100 the sum of the areas of the leak and the full open area times the position fraction is used with a flow exponent of n 0 5 mass flow rate Aieak position 100 Atutiopen 0 63 SQRT 2 rho SGN dp ABS dp 0 5 The abrupt change of the flow exponent n may lead to small discontinuities in the actual flow and the n50 value when opening closing a small window with a large leak 6 10 Flow controllers In the lower frame is a check box to make the ventilation component a flow controller The flow rate to inside or to outside can be limited interpret to inside as the startup direction of the arrow Don t zero both limits as a constant zero flow rate will result 6 11 Clicking on a room Clicking a room opens a movable input frame with the volume the temperature and the mechanical flow rates see Error Reference source not found 6 12 Changing the Conditions Stop the calculations The sliders at the bottom of the screen adjust the win
14. namical calculations elapsed real time equilibrium value extract Flow controllers flow exponent flow rate frame IAQ inlet Large windows leak leakage mechanical ventilation Mechanical meteo conditions n50 Natural ventilation Manual NaVIAQ page 10 flow rate For one person ventilation flow rates of 7 to 10 dm s are common pressure difference of 1 N m area for 1 dm s at 1 Pa unconfortably high CO concentration CO bar is red other rooms along the corridor blue and yellow Use of large windows to get a large amount of ventilation in a room for a limited period of time for instance 1 to a few hours per day ventilation flow rates indicate CO concentration other rooms along the corridor button at main screen that opens a form that may have advise on the input and allows for automatic adjustments Meteo outdoor temperature during the year and wind speed the result of human exhalation in dutch the word Delft is related to digging The main institute of TNO is in Delft The relation between research and digging Pipe though which the ventilation air is supplied or exhausted The ventilation and concentrations in this model are simulated as a true function of time and thus dynamical time elapsed after pressing the start button steady state value exhaust open Help Search forward in report and help text Search backwards in report and help text devices that keep the flowrate constant Power t
15. o which the ratio between two pressure differences across an air leak or opening has to be raised to get the ratio of the flow rates through the air leak opening at those pressure differences At laminar flow this exponent is 1 at turbulent flow this exponent is 0 5 There is a relation between the size of leaks the flow rate and the flow exponent but this relation has wide deviations for individual leaks Air flow rate here expressed in dm s Computer term for a rectangular line For example the frame that is opened after a click at an arrow or in a room in NaVIAQ Indoor Air Quality Opening grille flap or device through which ventilation air can enter the building This is for purpose provided more or less continuous inlet of air In contrast the air that enters through leaks is considered to be unintended or non purpose provided windows with openings in the order of 0 5 to 1 m Openings cracks joints that are not perfectly air tight through which ventilation air can enter the building These leaks are not purpose provided Ventilation by means of electrical fans ventilation driven by electrical fans wind speed wind direction and outdoor temperature Index for the air leak of the envelope of a building It is the number of air changes at a pressure difference of 50 Pa across the whole envelope of a building This is commonly measured by means of a blower door A large fan placed in an external door or window to
16. s starts with the input from the last closed run Manual NaVIAQ page 2 3 Top of the screen Position of windows and doors in the blue rooms Position of windows and doors in the yellow rooms olx D Number of blue rooms The yellow ones fill the remainder of the corridor E NaVIAQ Y1 3 NatYent TM IAQ Office ventilation Fl help S start Stop C C02 ESC exit File Units Help Number of rooms Pressure concen Also or on a 101 key keyboard lt TOOMS gt m rooms type rooms type2 i T 0 62 Pa Aas type 116 es feos type 244 cg 374 ppm F pos no North pos no North Youth i window jo fo window 9 fo doorfo fo dorfo fo persons gt 2 persons 9 2 entrance doorfem2 Jan Temperature C f18 Cross section SAS Wind The cross section of these rooms Leakage and temperature of direction is shown at the middle of the both staircases screen The view direction is to the right At the top of the screen is the menu to open save the building data change units and get help and open this manual The white text boxes except the one for the number of yellow rooms can be edited to modify the building At the left hand side is the floor plan of the office building The number of rooms counted along one side of the corridor is 1 to 50 The two green rooms are shown in detail below as a cross section 90 rotated
17. the program uses the just Saved input Input is also saved when NaVIAQ is closed If more than one instance of NavlAQ is running the last closed one determines the input at a next start of the program Keep in mind which program is the first on the Windows taskbar 8 Limitations NaVIAQ is meant to demonstrate office ventilation Real simulations and design issues would require much more detailed input such as wind wind pressures surrounding buildings detailed floor plan of the building other levels e Wind direction is faked by a cosine and will deviate from an actual course e Pressure coefficients are fixed shielded or exposed buildings must be simulated by an adapted wind speed The volume of the rooms is limited between 20 and 200 m The flow exponent has a fixed dependency with the input area For opening positions gt 0 n 0 5 The flow rates are linearized below 1 Pa The CO production per person is an average human production value of 5E 6 m s The CO concentrations are not calculated if rooms with less than 1 5 dm s per person exist The open windows and doors are still small areas meant as provision for ventilation They are at 100 open in the program some 20 to 50 times smaller than actual fully opened windows and doors Manual NaVIAQ page 9 9 Wordlist 1 dm s 1 Pa 12 cm 1500 ppm adjacent rooms airing arrows bars blue Check the input climate CO concentrations Delft duct dy
18. ut areas are the free cross section of the openings opening corrected for frame and grilles and other obstacles of a sharp edged opening that would lead to the same capacity dm s at 1 Pa An opening of 12 cm leads to 1 dm s at 1 Pa Volume of the room Flow rate dm3 s from the ventilation simulation Name of the room For the corridor this is the volume per Limitation dm3 s of room South length of the flow rate to inside volume m3 200 0 a room along the in case of a flow corridor nr persons f2 controller mech supply dm3 s fp Limitation dm3 s of the Area or free cross mech extract dm3 s 9 flow rate to outside in case section of the of a flow controller ventilation component Ventilation 26 Shows the area of each start 2 ventilation component pressure Pa gt gt IV press CO2 ppm foo are ure This check box controls the Figure 4 display of the area and limits as Figure 5 shown above The input for the adjoining blue yellow rooms of type 1 and 2 are copied from the 6 links in the cross section However the window and door positions are taken from the blue and yellow frame top right The staircase is derived from the leaks in the room at the same side of the building The staircase has twice the width of a room A click at one of the three rooms in the cross section opens figure 5 with Volume temperature mechanical supply and extract flow rates and
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