AM 11 Document - Bentley Communities
Contents
1. Legibility of digital file Good M Poor O Bad O Is all output contained Yes M No O Are algorithm level outputs accessible Yes M No O B1 7 Linked modules CAD input Yes O No M Vendor s own interface Yes M No O Other cad system s name AutoCAD DXF files Comments The software uses AutoCAD DXF files as a template for inputting data B1 8 Associated databases Thermophysical properties Yes M No O Basic material properties Yes M No O Properties of complete construction Yes M No O Transmission of windows Yes M No O Comment Weather data Yes M No O Worldwide Yes M No O Number of sites 7900 Comment Other databases 3 Check that the modules are available and working consult vendors about likely future releases Ask how many entries are in each database ask to see some of their contents 5 of 14 Communities AM 11 Document B1 9 User support Manuals User manual Yes M No O Hard copy Yes O No M On line Yes M No O Date of the latest copy May 2014 Does it include example problems with the expected answers Yes M No O Do the problems exercise all program modules Yes O No M Does it explain how to use every module Yes M No O Comments Technical manual Yes M No O Hard copy Yes O No M On line Yes M No O On line help Yes M No O Comments Case studies Vendor s case study examples obtained Yes M No O Case studies of others obtained Yes O No M Hotline Hotline support Yes M No O Turn round Instant2. List types of machine known to be suitable 3 0f 14 Communities AM 11 Document B1 3 Program code Type of code Compiled code only Yes W No Oo Source code available Yes E No Vv Extra for source code Yes O No Vv Programming language Fortran mi C C Notes B1 4 Modelling methods The Design Simulation program uses the EnergyPlus simulation engine B1 5 Input interface Type of interface GUI WI Menu driven O Command line 0 Other Digital data file Program produces accessible and human readable digital data files Yes M No O Legibility of digital file Good M Poor O Bad O Is entire problem definition contained Yes M No O Are all simulation parameters included Yes M No O Data checking Does program check for consistency and plausibility of input Yes M No O Interfaces may generate files e g binary files which cannot be read by people but only by the program interface These are much less useful and old binary files may cease to be readable by new versions of the interface Check that all the data are included e g geometry construction and occupancy data and that the weather file used is noted Check that all the simulation control information such as time step length length of preconditioning and convergence criteria is given Aof 14 Communities AM 11 Document B1 6 Output interface Type of interface GUI Vv Tabular O Digital O Digital data Is digital output accessible Yes M No O
3. 2 A program may have a number of listed capabilities Space is provided to elucidate the description List previous names by which program known significant advances in functionality and dates of these changes of platform and changes of vendors This information will help in the understanding of published literature especially about validation studies 20f14 Communities AM 11 Document B1 2 Computer specification Platform and operating system PC Yes M No O MS dos d Windows 3 x O Windows 95 d Windows nt O Windows XP VI Windows Vista M Windows 7 Mi Windows 8 Mi ps2 os2 Unix Yes O No Mi Apple Macintosh Yes O No Vv Comments Can be run from either the PC or the Server Machine with Control from a License Manager run from PC or online Processor storage and peripherals Processor speed 3 GHz recommended quad core Minimum RAM 2 GB recommended 4 gigabytes Minimum disk space 10 GB Other devices Floppy disk Yes O No mi CD rom drive Yes W No 0 Printer Yes W No E Plotter Yes W No E Digitising table Yes O No Vv Other Plotter is optional A LAN connection is required Other requirements Screen resolution gt 800x600 Internet connection required for update patches network or Internet connection required for license manager Suitable machines Most modern PCs will have no trouble running the software 3 r F Consider screen size video RAM Internet connection local area network connection etc
4. Cammu cos AM 11 Document Introduction Building service design is now frequently carried out using building energy and environmental modelling BEEM or design simulation software BEEM software can produce very different results depending on how the modelling software is used The AM11 document allows the user to examine a number of criteria to aid in their selection of the software that they wish to use AM 11 is not an accreditation document 1 of 14 Communities AM 11 Document Appendix B Checklist for choosing BEEM software This checklist complements section 4 of the CIBSE Applications Manual AM11 1998 Building Energy and Environmental Modelling B1 General B1 1 Program description Name vendor origins Program name Design Simulation Version V8i Date of current release Feb 2014 Vendor s name Bentley Systems UK Ltd Contact name Stephen Brown Vendor s address 20 Gracechurch Street 9 Floor London EC3V OBG Tel 0808 101 9247 Fax E mail via www Bentley com Program type Thermal analysis Load calculation M Plantandcontrols MJ Energy simulation M Lighting and visualisation Electric lighting Ml Daylighting MI Combined vi Air movement vi Specialist tool Vv Further description Program history Description Design simulation was first produced in 2007 and incorporates Hevacomp CAD input The simulation engine is EnergyPlus i The classification of programs is explained in Section
5. O idayM gt 1day 10 F ied Ask to see the manual Ensure that it contains all the useful features and that it is up to date 6 of 14 Bentley Communities Software Updates provided Media for dissemination Training Courses provided Cost Length Frequency B1 10 User base Numbers AM 11 Document Yes M No O Floppy disk O CD O _ Internet M Yes M No O On request Users in UK 10 500 Users worldwide 11 800 Sites in UK 1 500 Sites worldwide 1 630 UK building services engineers UK architects UK builders UK others Is there a user club Contacts Name Address Tel Fax E mail 10 500 Yes O No M Support and Sales 20 Gracechurch Street 9 Floor London EC38V OBG 0808 101 9247 via www Bentley com 7 of 14 Bentley Communities AM 11 Document B1 11 Cost Software and associated databases Core program on request Modules Name Name Name Databases Name Name First year user licence fee on request Total software and data Computer Name Annual recurring licence fee after first year of use Typical training course fees per year B1 12 Accuracy Has the program been evaluated Does the vendor exercise routine in house quality testing Yes M No O Yes M No O Complete the table below to document the validation history Independently i Date tested or by vendor v Type of test A C E Source of information Co
6. control is possible i e that a specified set point can be quickly achieved provided plant capacities are sufficient this is usually adequate for long term energy calculations In some programs the impact on temperature of alternative forms of control can be explored The ability to schedule heating and cooling plant and the occurrence of internal heat gains is important Some programs are very flexible enabling minute by minute variations others are less flexible 13 of 14 Caminu cos AM 11 Document B2 5 Observations 28 i siisi Record here any other general observations about the capabilities of the program which have not been covered elsewhere For example some programs impose geometric description limits on the maximum numbers of zones surfaces per zone or windows per surface 14 of 14
7. ed with convective sources The ability to specify the latent proportion of casual heat gains may be similarly important particularly regarding cooking equipment Some programs use detailed models e g which incorporate a time delay and an exponential temperature rise so that heating plant can be more accurately modelled This is less important for long term energy calculations than for short term temperature predictions gt An ability to calculate the latent cooling load will be particularly important in humid environments The ability to do this implies that the moisture content of the air is tracked by the program few programs do this 12 of 14 Communities AM 11 Document Controlling plant Free float Yes M No O Idealised control Yes M No O Ideal preheat cool Yes M No O Fixed heat injection Yes M No O On off thermostat Yes M No O Accelerator Yes M No O Proportional Yes M No O Proportional plus integral Yes M No O Proportional plus integral plus derivative Yes MW No O Advanced e g fuzzy logic adaptive self tuning neural network Yes O No M Other Schedules Repeated daily schedule Yes M No O Repeated hourly schedule Yes M No O Seasonal variations Yes M No O Flexible hourly schedule Yes M No O Notes Sensor types Sensing air temperature Yes M No O Mixed radiation and convection sensing Yes M No O Surface temperature sensing Yes O No M Intraconstruction sensing Yes O No M Notes a Most programs assume perfect
8. mments on the results Aug 07 i E CLG Part L Accreditation test Nov 07 i A ASHRAE HVAC Tests Nov 07 i A ASHRAE Fabric tests Nov 07 i A ASHRAE 120 Nov 07 i A BESTest July 09 i ACE CLG Part L Accreditation A Analytical verification C Intermodel comparison E Empirical validation 8 of 14 Communities AM 11 Document B2 Thermal simulation programs theoretical basis B2 1 Conduction and thermal storage Solution method Explicit finite difference M Implicit finite difference E Respnse factor WI Weighting factors O Other Time step length User specified Vv Calculated by program E Opaque surface conduction model One dimensional MI Three dimensional O Opaque layers node placement Fixed at number Vv User specified O Not applicable E Other Glazing conduction model Resistance or U value O Multi layer with nodes M Other Air gaps User specified resistance O Program calculated resistance Mi Other Initial node temperature User specified O Program calculated vi Notes 5 Preconditioning time User specified O Program recommended Vv 11 Bodh Ye er Validation work indicates that conduction and thermal storage are well modelled in the programs studied Alternative approaches generally have little impact on results and a small impact on program run times The ability to conduct three dimensional analyses is rarely needed For modelling a large area of glass especially hea
9. ng and casual gains Heat input Combined radiant and Separate fixed radiant and convective O convective components M Notes Cooling Sensible cooling only O Sensible and latent cooling M Notes 22 F 5 we P j i If a separate treatment is adopted for external convection note whether a fixed coefficient is used or a more detailed algorithm which may account for wind speed direction and surface orientation is used Although a rigorous approach is theoretically preferable wind speeds and directions close to surfaces are difficult to calculate 3 Longwave heat loss to surroundings has a significant impact on the temperature of external surfaces and for glazed surfaces and other poorly insulated areas the temperature of the interior spaces This has a significant impact on the comfort conditions and perhaps the demands for heating in highly glazed spaces such as atria The exchange may be modelled by a single coefficient or a detailed algorithm may be adopted The algorithm may calculate exchange to both the sky and surrounding surfaces ground and buildings or to just the sky The method of calculating the sky temperature should be noted 4 Heat input from plant and casual sources people lights and equipment may have fixed radiant and convective components or the user may be able to specify these The ability to specify will be important if for example a highly radiant source is used or if highly radiant sources are combin
10. owever adequate for most spaces and where long term energy use predictions are required Note whether the approach used for glazing is the same as that used for opaque surfaces Ignore if separate convective and radiant exchange networks are employed 13 Ignore if combined coefficients used In reality coefficients vary depending on the surface to air temperature difference surface length or height roughness etc Note the algorithm used to describe these effects Ignore if combined coefficient used A star network balances radiation exchange at a fictitious central node Radiation actually occurs by intersurface exchange A view factor calculation is needed to describe the intersurface visibility Note whether exact or approximate view factors are used and whether the program calculates these The heat exchange at external surfaces may be calculated using a simple combined surface heat transfer coefficient or by separating out convection and radiation and modelling each of these in detail Note whether the approach used for glazing is the same as that used for opaque surfaces 11 of 14 Cammu ics AM 11 Document Fixed user defined O Program calculated once O Calculated at each time step vi External convection coefficients Fixed user defined E Program calculated once O Calculated at each time step v1 Notes External longwave exchange User or program calculated coefficient O Detailed algorithm Vv Notes B2 4 Heating cooli
11. t absorbing glass windows are best modelled as multi layer constructions 9 of 14 Cammu itas AM 11 Document B2 2 Solar radiation External solar radiation Direct and diffuse Separate treatment of combined O direct and diffuse Vv Ground reflection of radiation Considered M Not considered O Diffuse radiation sky model Isotropic E Anisotropic mi Notes Window transmission direct User specified Vv Program calculated Vv Other notes Window transmission diffuse User specified Vv Program calculated Vv Other notes Internal solar distribution User specified fixed to Calculated once by one or more surfaces E program O Calculated at each time step Vv Notes 12 Eoi r n T Solar radiation and its reflection are best calculated if the direct and diffuse radiation components are separated Ground reflection must be calculated especially for more highly glazed spaces such as atria Anistropic diffuse solar radiation models are generally considered superior Window transmission may be calculated by the program or the user may specify incidence angle dependent values For direct solar radiation incidence angle dependent transmission and reflection or absorption properties are necessary a single value is often used for diffuse radiation Correct specification for direct radiation is most important Software is available to calculate incidence angle dependent values if programs require
12. users to specify these and databases are inadequate The distribution of internal solar radiation is usually important only where glazed areas are large surfaces have very different thermal mass or a number of surfaces are glazed The retransmission through other glazed surfaces can be very important for modelling e g conservatories or atria note the treatment of this effect 10 of 14 Communities AM 11 Document B2 3 Surface heat exchange Internal surfaces Combined convection and Separate convection and radiation coefficient O radiation networks Vv Internal combined coefficients Fixed user defined O Program calculated once O Calculated at each time step E Notes Internal convection coefficients Fixed user defined O Program calculated once O Calculated at each time step Vv Notes Internal longwave exchange Star network E IntersuArface exchange M Notes External surfaces Combined convection and Separate radiation and radiation coefficient O convection networks vi External combined coefficients 1Some programs calculate heat exchange between surfaces and the enclosed air using a coefficient which describes both the convective and longwave effects With such an approach the calculated space temperature is not a true air temperature it is often termed the enclosure temperature The true effects of highly asymmetric radiant environments e g a radiant ceiling panel are poorly predicted The approach is h
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