Building Performance Modeling: How to Use Modeling Analysis to Optimize Design Performance
1. 1- introduction- what is modeling BPM slides 2. There are muultiple reasons to model- bechmark, code compliance 3. Show integrated design, times to model 4. Early design 5. Middle design- parmetric study 6. Whole building design model- appendix G TOOLS 7. Trends
3. YRG sustainability consulting - education - analysis Design & Construction Business & Operations Communities Education & Training Marketing & Media
4. Learning Objectives Describe capabilities of building modeling Recognize model outputs Be familiar with when simulation can be used to assist design decisions Understand how modeling analysis can be implemented into your projects
5. Agenda Building Performance Modeling Design Assistance Compliance – Benchmarks Simulation tools Integrated Design Process
7. Building Performance Modeling What is a Building? Shelter for occupant comfort What is Performance? “The manner in which or the efficiency with which something reacts or fulfills its intended purpose” What is Simulation? Computer program for representation of the behavior or characteristics What is Building Performance Modeling?
19. HVAC AND CONTROLS RENEWABLE ENERGY WHOLE BUILDING ENERG MODEL ENERGY COST BUDGET DEMAND REDUCTION PARAMETRIC ENERGY USAGE ENVELOPE AND DAYLIGHT RADIATION AND DAYLIGHT ORIENTATION AND PLACEMENT CLIMATE AND CONTEXT When Is The Right Time For You? 1 2 3 4 5 Model Outputs
28. New York Denver °F Phoenix Hong Kong 113+ 104 95 86 77 68 59 50 41 32 Annual Temperature Profile
29. Cold Stress 7000+ hours Comfortable 900+ hours Heat Stress 200+ hours Source:: Denver, CO TMY3 Weather Data Thermal Stress
30. Observation Constant annual rainfall Combination of high humidity and constant rainfall makes it a wet climate Recommendation Design for water proofing and moisture penetration Annual rainfall 683.0 mm (26 inches) Driest month Oct with 40.0 mm rainfall Wettest month Jun with 90.0 mm rainfall Monthly Rainfall
31. New York Wind Speed and Direction Actual Weather and Desired Comfort Annual Wind, Temperature and Humidity Analysis
32. Floor Area= 9,600 SF Building Volume = 96,0000 cu.ft. Massing 15,200 SF 6,014 SF 23,200 SF SURFACE AREA : SPACE VOLUME 0.15 0.063 0.24 Envelope Area : Volume Ratio
33. June 21st @ 9:00 am United Nations Building – New York, NY Building Orientation – Solar Access N Actual Rotated 90 degrees
34. Energy Efficiency Measure: Building Shape Annual energy savings = 1.6% or 120,000 rupees Square 53.8 kBtu/SF/yr ‘H Baseline’ 54.7 kBtu/SF/yr
35. Energy Efficiency Measure: Roof Insulation Annual energy savings = 0.4% or 28,000 rupees R-40 54.5 kBtu/SF/yr R-15 54.7 kBtu/SF/yr
39. East Solar Location- Low Best practice- Vertical fins West Solar Location- High Best practice- Horizontal Overhangs Sun Path- East and West Façades
40. All Vertical Fins All Horizontal Shades 20% Combination 30% 40% Shading System Optimization- Solar Radiation Analysis
41. 1:4 1:3 1:2 1:1 Further Shading System Optimization – Vertical Fin Performance Metric
42. Depth-to-Distance Ratios Horizontal Fins Fin Façade (~84°) Max Incline Condition 1 to 2.8 ratio Tower Interior Max Summer (75.9°) Max Winter (29.0°) Fin Façade (~90°) Typical Condition 1 to 3.6 ratio Tower Interior Max Summer (75.9°) Max Winter (29.0°) Shading Fins – Range of Performance
43. Recommendations Cumulative Solar Exposure, Summer Season 2010.09.04 Shading Devices – Summer Heat Gain Comparison
45. 3D Models Beyond Design DWGs Mech. Zoning Occupancy Equipment Lighting Use Set points Efficiencies Schedules Information…. Information Source: Moma
50. Emphasize on reduction of electrical energy consumption through lighting, cooling, fans, and pump efficienciesGround Source Heat Pump- Saving 2% of total building energy
62. Climate Classification The blue line is the temperature and humidity profile through the year. The site is in a cold climate majority of the time, and warm and dry for a short time of the year. Use the “moderate” period for passive cooling and heating, free cooling and economizer cycle.
63. Qc + Qv + Qr + Qi + Qe = 0 Qc = Conductive Gains Qv = Ventilation Gains Qr = Radiant Gains Qi = Internal Gains Qe = Evaporative Gains Mechanical Systems to provide thermal comfort.
65. Key Results 21 AUG 4PM West Wall Clear Glass Intolerable Glare
66. Scale 0-500fc Scale 0-25fc. The colored area is below 25 FC 12% LEED Compliant FTE Spaces (9am) 9% LEED Compliant FTE Spaces (3 pm) Daylight- Quantitative Analysis
67. Jersey City Municipal Services Complex Design Optimization no shelf exterior shelf only exterior/interior shelf Solar Shades Light Shelves Reduced summer heat gain Even distribution of illumination Office Building Light Shelf Study
68. 1 ft. Shelf Depth 2 ft. Shelf Depth Shelf covers a glare source Finding: Uniform Daylight distribution with increase in shelf depth Office Building Light Shelf Study
Modeling can serve all sizes of purpose and goals. DIFFERENT tools at different times.
ASHRAE is planning to reduce it’s baseline energy use to 0 in next 20 years, that includes some power generation. It is very possible to reduce passive+active energy use by 60-70% with efficient design. Current standard 189 provides guidance to reduces energy use by 30%, so another 30 is easy with some more integrated design
TALKING POINTS:Envelope to Floor / Volume Area RatioRoof to Wall RatioForm impactsConductionHVAC distributionDaylighting / Natural VentilationForm is impacted byContext and microclimate FormBuilding Surface AreaEnvelope Area/ Space VolumeConduction (heat loss in winter)DaylightingNat VentilationHVAC DistributionRoof/WallContext/Micro-climate
TALKING POINTS:Solar heat gainWindRadiation
Not sure if this is a good slide to show, yet
Doesn’t account for lighting controls, yetCentral chillers
YRG developed a baseline case energy model compliant with ASHRAE 90.1 YRG developed a Proposed Design case energy model representing the actual project design with all Energy Efficiency MeasuresThe model was able to estimate energy savings of the project relative to the ASHRAE baselineUtilizing energy costs of the project for the site, these energy savings translate to operational cost savings
Modeling allows u to predict operating energy use, and possibly borrow from there into capital cost expenditures, with a promise to pay back.
Energy is neither created or destroyedAll energy gains have to balance each other out. If there is too much conduction, then ventilation or evaporative gains have to be –ve or provided by mechanical system
Tools used- Evalglare/Radiance
For vapor diffusion and liquid transferWUFI-ORNL/IBP can be used for assessing the drying time of masonry with trapped construction moisturethe danger of interstitial condensationthe influence of driving rain on exterior building componentsthe effect of repair and retrofit measuresthe hygrothermal performance of roof and wall assemblies under unanticipated use or in different climate zones.
Trends section of PA part 2Current trends in building performance modeling- 45minuteso Energy modeling usage statisticso BIM integrationo Metered data/ calibration- M&V, and also going back and calibrating EB modelo BIM integration- talk about Port Authority’s BIM usage. Integration into operationso After occupancy modeling (talk about BIM and its capabilities from design through ops)o Online dashboards – slide from Trendso After occupancy modeling (talk about BIM and its capabilities from design through ops)
Trends intro
Rapid energy modeling an emerging trend, we are validating its accuracy
Trends intro
Existing building energy usage model – Harvard Gund Hall Example
Web based monitoring
Web based monitoring
BIM and GIS integration, potential for collection of energy data for entire portfolio of existing buildings. (Onuma)
