Energy Efficient Windows and Building Design * Software Workshop * Building Simulation Tools

1. Energy Efficient Windows and Building Design* Software Workshop *Building Simulation Tools New Delhi - November 22-23, 2002 Bangalore - November 25-26, 2002 Instructors: Bipin Shah, NFRC Charlie Ćurčija, CEERE Mahabir Bhandari, CEERE Sponsored by: U.S. Department of Energy(DOE) National Fenestration Rating Council (NFRC) Center for Energy Efficiency and Renewable Energy at the University of Massachusetts (CEERE)

2. Overview • Why building simulation (BS) tools? • Application of BS tools • Available BS Tools • How to choose a simulation tool? • Performing building simulation • Example: Case Study Center for Energy Efficiency and Renewable Energy, UMass, Copyright, 2002

3. Why Building Simulation (BS) Tools? • To answer “What If” questions • An inexpensive means for exploring a plethora of different design options and HVAC systems • Aid in the analysis of energy usage in building • Energy conservation studies • Building design studies • Energy saving potential: energy efficient design and operation • Building performance involves complex interactions and designer can experiment with different strategies quickly • Help in designing the buildings to conform with Building codes Center for Energy Efficiency and Renewable Energy, UMass, Copyright, 2002

4. Application of BS Tools • Building heating/cooling load calculation (peak energy Demand and its profile) • Building energy performance analysis, • Building energy management and control system design, • Building regulations/codes/standards compliance checking • Life Cycle Cost analysis • Quality Assurance (Commissioning) Center for Energy Efficiency and Renewable Energy, UMass, Copyright, 2002

5. Available BS Tools • DOE-2 : Whole building analysis program • Interface as eQuest, PowerDoe, VisualDoe, etc. • BLAST: building Load Analysis and System Thermodynamics. Uses heat balance method • EnergyPlus : Combination of DOE & Blast + additional features • Energy10 : For residential and small commercial buildings I.e. buildings with one or two zones or small (<10, 000 ft2) • Building Design Advisor: Early stages of design and optimization • TRNSYS : Designed to simulate the transient performance of thermal energy system Center for Energy Efficiency and Renewable Energy, UMass, Copyright, 2002

6. BS Tools Contd. • TSBI3 : Easy to use flexible program developed by Danish Building Research Institute, Modular • ESP-r : Major European tool. Public domain program, only Unix env., self learning modules • COMBINE : Integrates more than 10 design tools into an Intergraph based architectural CAD system • More information on these and other simulation tools: www.eren.doe.gov/buildings/tools_directory/ Center for Energy Efficiency and Renewable Energy, UMass, Copyright, 2002

7. Specialized/Component Tools • To provide the detailed description of key components such as • Detailed Frame calculations • Thermal bridges or 2-D heat transfer at window wall interface • Air flows • Fenestration systems • The detailed results are more accurate and act as input to the whole building simulation model Center for Energy Efficiency and Renewable Energy, UMass, Copyright, 2002

8. Specialized/Component Tools: Partial List • For daylighting • Superlite, Radiance • For building envelopes: • THERM: Detailed 2D Analysis of heat transfer • WINDOW/OPTICS: Fenestration heat transfer, solar heat gain and solar-optical properties • For selecting energy efficient fenestration: RESFEN • For multi-zone airflow: COMIS • For moisture transport phenomenon : WUFI Center for Energy Efficiency and Renewable Energy, UMass, Copyright, 2002

9. Life Cycle Analysis Tools: Partial List • BEES 2.0 • Based on consensus standards (ASTM E917, ASTM E1557, ISO 14040 and ASTM E1765) • www.bfrl.nist.gov/oae/bees.html • BLCC • Evaluation of Energy & water conservation and Renewable energy projects; Comparative economic measures • www.doe2.com • ATHENA • environmental measures: embodied energy, resource use, air and water pollution, greenhouse gas effects and total solid wastes produced. • http://www.athenaSMI.ca • LISA • LCA in Sustainable Architecture • Most case studies for Australia and UK • LCCID • Ranking of projects, savings-to-investment ratio, discounted payback period • University of Illinois, UC • Envest • For Office building : - ecopoint • Available from BRE UK Center for Energy Efficiency and Renewable Energy, UMass, Copyright, 2002

10. DOE2 • A public domain program for building energy analysis; sponsored by DOE • It is a portable FORTRAN program and can be used in large variety of computers including PCs • Predicts hourly energy use and energy cost • INPUTS: Hourly weather information, building description and HVAC system and utility rates • Structure • BDL, Loads, Systems, Plants and Economics • Sequential method to link these models • Uses weighting factor method • Default libraries for building construction • Can use Metric and English units • Uses • Energy conservation studies • Building design studies Center for Energy Efficiency and Renewable Energy, UMass, Copyright, 2002

11. DOE 2 flow diagram Keyword file (BDLKEY.BIN) Std Lib (BDLLIB.DAT) Weather processor User lib (USRLIB.DAT) Packed weather Center for Energy Efficiency and Renewable Energy, UMass, Copyright, 2002

12. DOE2: Input File Format • DOE2 uses BDL Language processor • KEYWORDS are used for the description "Dirt" = MATERIAL TYPE = PROPERTIES THICKNESS = 2 CONDUCTIVITY = 0.5 DENSITY = 100 SPECIFIC-HEAT = 0.25 "Cons 8in CMU" = CONSTRUCTION TYPE = LAYERS ABSORPTANCE = 0.65 ROUGHNESS = 2 LAYERS = "Lay 8in CMU" … "East Wall Z1" = EXTERIOR-WALL CONSTRUCTION = "Cons 8in CMU" .. "Lay 8in CMU" = LAYERS MATERIAL = ( "Dirt", "CMU HW 8in ConcFill (CB12)", "Polystyrene 1.25in (IN34)", "GypBd 1/2in (GP01)" ) .. Center for Energy Efficiency and Renewable Energy, UMass, Copyright, 2002

13. DOE2 : GUIs • BDL file is difficult to create and users need to remember a number of related keywords • Graphical User Interfaces: • eQuest : Freeware and easy to use. PowerDoe : Graphical presentation of both building description and display of results • PowerDoe: Comprehensive GUI • VisualDoe : Rooms can be represented by block, ease facades, design alternatives of drag drop, Custom block editor, custom • Other… Center for Energy Efficiency and Renewable Energy, UMass, Copyright, 2002

14. DOE with GUI: eQuest • Easy to use and free simple Graphical User Interface for quick energy analysis • Only 31 sheets of details and can be mastered in 2-3 hours • Default values and online help available • Uses DOE 2.2 as simulation engine • Wizard mode has no flexibility of changing data but user inputs can be provided in spreadsheet mode and/or by editing the default library Center for Energy Efficiency and Renewable Energy, UMass, Copyright, 2002

15. eQuest: Wizard Center for Energy Efficiency and Renewable Energy, UMass, Copyright, 2002

16. eQuest: Important Data • Building geometry : • Footprint shape :Triangle, rectangle. L shape, T shape, + shape, U shape, H shape (accordingly the length and width parameters) • Number of floors – floor height • Zoning pattern: 1 per floor, Perimeter/core • Construction: walls/roof, floors/ceiling • Windows – area, type, frame, overhangs/fins • Internal load • Lighting, Occupancy, Equipment with schedules • Distribution by spaces • HVAC systems • System description • Heating/cooling set points and Schedules Center for Energy Efficiency and Renewable Energy, UMass, Copyright, 2002

17. eQuest: Spreadsheet view Center for Energy Efficiency and Renewable Energy, UMass, Copyright, 2002

18. eQuest: Online Help Center for Energy Efficiency and Renewable Energy, UMass, Copyright, 2002

19. eQuest: 3D view Center for Energy Efficiency and Renewable Energy, UMass, Copyright, 2002

20. eQuest: EEM wizard Center for Energy Efficiency and Renewable Energy, UMass, Copyright, 2002

21. Summary of PowerDoe • Provides details specifications of building geometry and HVAC systems • Available online help • Libraries for construction, HVAC systems & weather locales; library can be modified or user specific library can be defined • Future additions: • Process refrigeration and equipment • Rule processor and automated design • Wizard for building types • Creating input data (building geometry) is very time consuming and requires a good amount of familiarity with the program • Availability : http://www.doe2.com Center for Energy Efficiency and Renewable Energy, UMass, Copyright, 2002

22. EnergyPlus • Development: It was becoming difficult and costly to maintain DOE and BLAST both supported by US government • Based on combined features & capabilities of BLAST & DOE2 but is a completely new program written in FORTRAN 90/95 • New features: • Integrated (simultaneous loads and systems) simulation • Variable time steps • User-configurable modular system • Multizone air flow • Moisture transfer in building components • Input and output structures tailored to facilitate third party dev. Center for Energy Efficiency and Renewable Energy, UMass, Copyright, 2002

23. Structure of EnergyPlus • Simulation Manager • Controls the interactions between all simulation loops • Modules are self contained • Heat and Mass Balance • Can connect to COMIS for multi-zone airflow • To WINDOW5 for fenestration • Building Systems Simulation • Controls the simulation of HVAC and elec. systems, equip, components • Input, Output & Weather Data • Can read data from CAD, DOE, BLAST • Readable but not user friendly • IAI developing an object oriented data protocol (IFC) for bldg inf. exchange • Very few default assumptions Center for Energy Efficiency and Renewable Energy, UMass, Copyright, 2002

24. Importing building geometry from CAD into EnergyPlus • Software interoperability for direct exchange of data among different software • The exchange requires a data model • Data model is called International Foundation Classes (IFC) • Data model supports the 3D definition of building geometry • Building Geometry from CAD can be imported to EnergyPlus via BSPro developed by Olof Grandlund, Finland Center for Energy Efficiency and Renewable Energy, UMass, Copyright, 2002

25. Energy Plus Screen Center for Energy Efficiency and Renewable Energy, UMass, Copyright, 2002

26. Summary of EnergyPlus Features • In the preliminary stage of development • Modular structure gives flexibility of adding interfaces and components • More accurate simulation engine than DOE and BLAST • Time consuming task of building geometry input will be drastically reduced by use of IFCs • Version 1.0 is available and is free of charge from: http://www.eren.doe.gov/buildings/energy_tools/energyplus/ • BSPro Com server for IC files is available at: http://www.bspro.net/ Center for Energy Efficiency and Renewable Energy, UMass, Copyright, 2002

27. BLAST • Uses heat balance approach • Sponsored by DOD • Version with interface available from University of Illinois Center for Energy Efficiency and Renewable Energy, UMass, Copyright, 2002

28. Energy-10 • For quick estimation • Integrates daylighting, passive heating and cooling technologies with an eff. envelope & equipment • For smaller buildings buildings (1 or 2 thermal zones) <=10,000 ft2 • Ranking of strategies Center for Energy Efficiency and Renewable Energy, UMass, Copyright, 2002

29. Building Design Advisor • Acts as data manager and process controller • Integrates use of multiple simulation tools and data bases • Current version has Daylighting (DCM), Electric lighting (ECM)and Energy analysis(DOE2) linked Center for Energy Efficiency and Renewable Energy, UMass, Copyright, 2002

30. TRNSYS • Transient performance of thermal systems • Modular approach to solve systems of components • Each component is a FORTRAN subroutine • New component can be generated easily • GUI IISiBat available Center for Energy Efficiency and Renewable Energy, UMass, Copyright, 2002

31. RADIANCE • Highly accurate ray tracing software • For analysis and visualization in lighting design • Predicts illumination, visual quality and appearance, performance of new lighting and daylighting technologies • Inputs: • Geometry, materials, luminaries, time, date , sky conditions Center for Energy Efficiency and Renewable Energy, UMass, Copyright, 2002

32. COMIS • Inter-zonal airflow model • Transportation of contaminants • Standalone or can be integrated into BS models • IISiBat as GUI Center for Energy Efficiency and Renewable Energy, UMass, Copyright, 2002

33. WUFI • Window based model for hygrothermal analysis of building envelope constructions • Influence of driving rain on exterior building components • Investigate the danger of interstitial condensation • Developed by ORNL and Fraunhofer Inst Center for Energy Efficiency and Renewable Energy, UMass, Copyright, 2002

34. BEES 2.0Building for Environmental and Economic Sustainability • Windows-based decision support software • Environmental performance based on ISO 14040 • Economic performance based on ASTM E971 • includes actual environmental and economic performance data for 65 building products Center for Energy Efficiency and Renewable Energy, UMass, Copyright, 2002

35. BLCC 5.0Building Life-Cycle Cost • Window based, programmed in Java with XML format • For energy and water conservation in buildings • Evaluates alternate design both in new and existing buildings • Calculates lowest LCC i.e. which design is most economical in long run • Economic measures for alternative design including net savings, SIR, adjusted IRR and payback period • Energy savings and emission reduction Center for Energy Efficiency and Renewable Energy, UMass, Copyright, 2002

36. ATHENA • Life Cycle Env. Effects of a complete structure or of individual assemblies • Presently steel, wood & concrete products and assemblies; • Experiment with alternative design and different material mixes • For low rise buildings – max upto 5 storeys Center for Energy Efficiency and Renewable Energy, UMass, Copyright, 2002

37. Selection of a BS tool • Need/purpose • Expertise • Performance • Computing ability • Usability • Data exchange ability • Database support • Budget/Cost • Software cost • Training cost • Using cost Center for Energy Efficiency and Renewable Energy, UMass, Copyright, 2002

38. How to perform building simulation • Selection of a tool • Mastering how to use a tool - Training • Defining the problem or identifying the opportunities • Specifying the model • Data acquisition : for representing the building and HVAC systems in the format of simulation tool • Implementation • Planning • Experimentation • Analysis of results and reporting Center for Energy Efficiency and Renewable Energy, UMass, Copyright, 2002

39. Summary • Summary of building simulation tools have been presented • A large number of tools are available • Proper selection and understanding of tools is important • Simulation tools can play a major role in energy conservation and Energy efficient design . Center for Energy Efficiency and Renewable Energy, UMass, Copyright, 2002