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ENERGY STAR Multifamily High Rise Program. Using the Simulation Guidelines July 2011. Performance Path Components. Prerequisites Performance Target Simulation Guidelines Performance Path Calculator Modeling Checklist Testing and Verification (T&V) Benchmarking using Portfolio Manager.
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ENERGY STARMultifamily High Rise Program Using the Simulation Guidelines July 2011
Performance Path Components • Prerequisites • Performance Target • Simulation Guidelines • Performance Path Calculator • Modeling Checklist • Testing and Verification (T&V) • Benchmarking using Portfolio Manager
Objectives of this Webinar • Explain how to develop the energy models • Review ASHRAE 90.1-2007 and its Appendices • Review the Simulation Guidelines
ASHRAE Standard 90.1-2007 • Similar to the RESNET Standard for residential and low-rise multifamily. • 90.1 is the energy standard for buildings except low-rise residential buildings. • Unlike RESNET, 90.1 is not automatically used in software to generate the baseline building. Only some software currently have this capability.
ASHRAE Standard 90.1-2007 • Section 1: Purpose • Section 2: Scope • Section 3: Definitions, Abbreviations, and Acronyms • Section 4: Administration and Enforcement
ASHRAE Standard 90.1-2007 • Section 5: Building Envelope • Section 6: Heating, Ventilating and Air Conditioning • Section 7: Service Water Heating • Section 8: Power • Section 9: Lighting • Section 10: Other Equipment • Section 11: Energy Cost Budget Method • Section 12: Normative References
ASHRAE Standard 90.1-2007 • Example:
ASHRAE Standard 90.1-2007 • Tables to know • Tables 5.5-1 through 5.5-8 (Building Envelope Requirements by Climate Zone) • Tables 6.8.1D, 6.8.1F and 7.8 (Minimum HVAC and DHW Equipment Efficiencies) • Tables 9.4.5 and 9.6.1 (Lighting power densities by space type) • Table 10.8 (Minimum Motor Efficiencies)
ASHRAE Standard 90.1-2007 • Appendix A: Rated R-Value of Insulation and Assembly U-Factor Determinations • Appendix B: Building Envelope Climate Criteria • Appendix C: Methodology for Building Envelope Trade-Off Option in Section 5.6 • Appendix D: Climatic Data • Appendix E: Informative References • Appendix F: Addenda Description Info • Appendix G: Performance Rating Method
Appendix A – R and U values • Example: Using Table A3.4 of Appendix A, R-13 cavity insulation installed in 2x4, 16”oc wood-frame walls with R-5 continuous, results in an assembly U-value of 0.059.
Appendix D – Climatic Data • Your software may automatically select the correct heating and cooling design temperatures based on the nearest city to your location. If not, Table D-1 can be used.
Appendix G – Performance Rating • G1 – General • G2 – Simulation General Requirements • G3 – Calculation of the Proposed and Baseline Building Performance • Table G3.1 Modeling Requirements • Table G3.1.1A Baseline HVAC System Types • Table G3.1.1B Baseline System Descriptions
Appendix G – Section G3 • Calculation of the Proposed and Baseline Building Performance • Table G3.1 Modeling Requirements • Table G3.1.1A Baseline HVAC System Types • Table G3.1.1B Baseline System Descriptions
Appendix G – Table G3.1 • Table G3.1 Modeling Requirements
Appendix G – Table G3.1, cont’d • Baseline Envelope • Roof: Insulation entirely above deck; reflectivity of 0.30 • Above-grade walls: Steel-framed • Floor perimeter: same as mass wall • Floors: Steel-joist • Vertical fenestration: area and orientation to equal Proposed Design, but NOT to exceed 40% of the gross above-grade wall area • Residential vs nonresidential
Appendix G – Table G3.1, cont’d • Residential Baseline Envelope for Zone 3 • Roof: Above deck, R-20 c.i., U-0.048 • AG walls: Steel-framed, R-13+R-7.5 c.i. • Floor perimeter: R-9.5 c.i. • Floors: Steel-joist, R-19, U-0.052 • Vertical fenestration: (SHGC-0.25, all frames) • Nonmetal framing: U-0.65 • Metal framing (curtainwall/storefront): U-0.60 • Metal framing (entrance door): U-0.90 • Metal framing (all other): U-0.65
Appendix G – Tables G3.1.1A & B • Baseline HVAC System Types & Descriptions
Appendix G – Table G3.1.1B • Baseline HVAC System Descriptions • 1: Hot-water boiler(s) and PTACs (6.8.1D&F) • 80% AFUE-82% Et and 9.3-11.0 EER • Pumps: 19 W/gpm, Supply @180F, Return @130F • Outdoor reset (G3.1.3.4) • 2: Packaged terminal heat pumps (6.8.1D) • 9.1-10.8 EER and 2.8-3.0 COP • 6.8.1D Example:12.3-(0.213*Capacity/1000) EER • Auxiliary heat only when outdoor temp is < 40F • Supply Fan Power: CFM X 0.3 (G3.1.2.9)
Simulation Guidelines I – Definitions 1 – Scope (page 5) 2 – Objectives (page 5) 3 – Modeling Guidelines (pages 5-27) Appendix A: List of Standards Appendix B: Description of Performance Path Calculator 20
Modeling Guidelines 3.1 General Approach 3.2 Performance Rating 3.3 Simulation Program 3.4 Opaque Assemblies 3.5 Vertical Fenestration 3.6 Lighting 3.7 Thermal Blocks 3.8 HVAC 3.9 Domestic Hot Water • 3.10 Plug Loads • 3.11 Elevator Loads • 3.12 Ventilation & Infiltration • 3.13 HVAC Distribution Losses • 3.14 Fan Motor Energy • 3.15 Pumps • 3.16 Energy Rates 21
3.1 General Approach • Baseline, Proposed & As-Built Components • End uses that do not exist • Code-compliant • Model as verified on-site • Some measured data (ie. envelope leakage) are part of program requirements, but are not updated in the model 22
3.1 General Approach • What to include and exclude • Include all residential spaces • Include all building related end-use loads • Include or exclude commercial/retail • Exclude credit for systems to be installed by owner or occupant • Schedules - lighting, temperature 23
3.2 Performance Rating • Baseline Building Performance (BaseBP) • Proposed Building Performance (PropBP) • Annual sum of predicted energy costs • Performance Rating=100*(BaseBP - PropBP) (BaseBP) • On-site power generation cannot be used to meet the 15% Performance Target • Some outside calculations permitted 24
3.3 Simulation Program • Must meet the requirements of Appendix G, Section G2.2. • Examples: DOE-2, eQUEST, TRACE, HAP and EnergyGauge. 25
3.4 Opaque Assemblies • Baseline walls, floors, roofs use Tables 5.5 • Proposed Design follows 90.1 Appendix A • Existing Buildings • Treat these as windows: • Through-wall AC sleeves • Doors that are more than 50% glass • Floor perimeter edges & balconies • Weighted U-values accepted • De-rate continuous exterior insulation
3.5 Vertical Fenestration • Distributed on each face of the Baseline building in the same proportion as the Proposed Design, without exceeding 40% of gross above-grade wall area. • Baseline window framing material* • Wood-frame buildings>>nonmetal frames • All other buildings>>metal frames • NFRC or official certification from installer • Assembly U-factor, not center of glass • Automatically-controlled shades or blinds and permanent shading devices *Indicates a deviation from ASHRAE
3.6 Lighting (General) • Power = lamp (bulb) + ballast • Model lighting power as installed, not based on maximum rated fixture wattage.* • ASHRAE: Max 100W, with 26W CFL 100W • EPA: Max 100W, with 26W CFL 28W • No credit for plug-in lighting • Credit for efficient lighting, but not insufficient lighting
3.6 Lighting (In-Unit) • Schedule: 2.34 hours per day • Baseline:1.1 Watt/ft2 • Proposed:1.1 Watt/ft2 where none specified • Where specified, the actual installed lighting power density (LPD) shall be modeled. • If supplemented by lighting via receptacles, hardwired fixtures can provide illumination at a rate of no more than 2 ft2 per Watt. • Overall LPD can be used in simulation.
3.6 Lighting (In-Unit), continued BR1 – 150 ft2 Kitchen - 200 ft2 Bath – 50 ft2 Hall – 100 ft2 Living Room- 300 ft2 BR2 – 150 ft2 950 ft2 x 1.1 Watts/ft2 = 1045 Watts 31
3.6 Lighting (In-Unit), continued BR1 – 150 ft2 Kitchen - 200 ft2 Bath – 50 ft2 Hall – 100 ft2 Living Room- 300 ft2 Unlit area – 100 ft2, assume 110 W supplied by occupant Lit area – 200 ft2, 100 W installed BR2 – 150 ft2 32
3.6 Lighting (In-Unit), continued BR1 – 150 ft2 None (165W) Kitchen - 200 ft2 57W Bath – 50 ft2 37W Hall – 100 ft2 56W Living Room- 300 ft2 Unlit area – 100 ft2, assume 110 W supplied by occupant Lit area – 200 ft2, 100 W installed BR2 – 150 ft2 None (165W) [165+37+165+56+57+110+100] ÷ 950 = 0.73 W/ft2 33
3.6 Lighting (Occupancy Sensors) • Appendix G, Table G3.2: 10% savings • EPA: 25-35%* • Ex. Baseline Stairs: 0.6 Watt/ft2, 24 hrs Proposed Stairs: 0.6 Watt/ft2, 15.6 hrs or 0.39 Watt/ft2, 24 hrs
3.6 Lighting (Exterior) • Include all exterior lighting connected to the building’s utility meters. • Use 90.1-2007 Table 9.4.5 for Baseline. • If it’s not specified in Proposed, it’s not modeled in Baseline either. • Building façade lighting penalty; no credit • Due to the required photosensors, model exterior lighting for only 12 hours/day.
3.7 Thermal Blocks • Unlike Appendix G, the EPA permits dwelling units that have different orientation and/or are adjacent to different types of surfaces (e.g. roof or slab) to be aggregated*. This is not required. • However, common spaces, utility areas and other non-living areas must be modeled as separate thermal blocks. • The thermal block configuration must remain identical between the Baseline Building and Proposed Design building models. *Indicates a deviation from ASHRAE
3.8 HVAC Conditioning of spaces must match in both models. Typical living spaces must be modeled as heated and cooled, regardless of what is installed in those spaces. Do NOT model cooling in corridors and utility spaces if the spaces are NOT cooled in the Proposed Design.* The Baseline HVAC system shall be modeled as per Appendix G, as described in previous slides. The Baseline equipment capacities shall be oversized by 15% for cooling and 25% for heating.
3.8 HVAC, continued • The same modeling method and/or efficiency units must be used in the Baseline Building and Proposed Design model. • Setpoint temperature of 72ºF and setback temperature of 70ºF shall be used for heating. • Setpoint temperature of 78ºF and setback temperature of 80ºF shall be used for cooling. • The hourly thermostat schedule is provided in the Simulation Guidelines.
3.9.1 Domestic Hot Water • Equipment Type and Efficiency • Unlike HVAC, Baseline DHW system type, capacity and fuel shall be the same as specified in the Proposed Design. • If a combined heating & hot water system is proposed, separate stand-alone systems for both heating and hot water must be modeled as the Baseline system. • See Table 7.8 for Baseline DHW efficiencies • Unfired storage tanks: R-12.5 insulation
3.9.2 Domestic Hot Water, cont’d • Baseline Hot Water Demand • Based on number of bedrooms in buildings, occupancy demographics, and the use of EPACT 1992 plumbing fixtures (2.5 gpm). • 12, 25, or 44 gallons per day per person, based on low, medium or high-usage. • Example: 50 unit low-income building, with 100 bedrooms, 100 occupantsX44=4400 gpd • Proposed Hot Water Demand is based on lower flow fixtures and any ENERGY STAR clothes washers and/or dishwashers.
3.9 Domestic Hot Water, cont’d • 3.9.3 Non-energy related Water Savings • 3.9.4 Hot Water Distribution System • Same piping area in both models • Hot water setpoint of 120°F in both models • If a hot water recirculation system is present in Proposed Design, it must also be included in the Baseline.
3.11 Elevator Loads • Use number of stories and units in Proposed Design with chart below to determine electricity consumption of Baseline elevator. • 10% of elevator energy usage shall be added to space heat gains. • Use same value for Proposed or to take credit, follow guidance in Simulation Guidelines.
3.12 Ventilation & Infiltration • General • Use the same infiltration algorithms in Baseline and Proposed (ACH, CFM/ft2, etc) • Software defaults for infiltration may be used in non-dwelling unit spaces • Exhaust ventilation can be combined with infiltration in the model • Measured infiltration rates are not used in the As-Built model, but must meet Prerequisites. • ASHRAE 62.2-2007 (apartments), 62.1 (other)
3.12 Ventilation & Infiltration Baseline Building • Ventilation rates shall be modeled in the Baseline using the same rates as the Proposed Design, without exceeding ASHRAE 62.2-2007 rates by more than 50%. • Bathroom exhaust: 20-30 CFM continuous; 50-75 CFM int. • Kitchen exhaust: 5–7.5 ACH continuous;100-150 CFM int. • ‘Whole-house’ ventilation: CFM=0.01*Area + 7.5 *(#BR+1) • Ex. 1000 ft2 3 BR unit requires 40 CFM of continuous ventilation. 2 bathrooms designed for 20 CFM continuous exhaust could simultaneously meet the whole-house requirement. Alternatively, one kitchen with a 100 CFM tenant operated fan could be set on a timer to provide at least 40 CFM each hour.
3.12 Ventilation & Infiltration Baseline Building • The combined modeled rate of mechanical and natural ventilation and infiltration in dwelling units shall be no less than 0.35 ACH or 15 CFM per person. • For common spaces: both outdoor air supply and exhaust systems shall be equipped with motorized dampers to automatically shut when the systems or spaces served are not in use. • No heat recovery shall be modeled, unless it is required by local code or Appendix G. • No demand control ventilation shall be modeled unless required by local or national code.
3.12 Ventilation & Infiltration Proposed Design • Ventilation rates shall be modeled based on design and design must meet ASHRAE 62-2007 Prerequisites. • The combined modeled rate of mechanical and natural ventilation and infiltration in dwelling units shall be no less than 0.35 ACH or 15 CFM per person. • Specified mechanical ventilation is permitted to exceed ASHRAE 62-2007 recommendations by more than 50%; there will, however, be an energy penalty associated with that over-ventilating.
3.13 HVAC Distribution Losses • Do not model piping or duct losses. • Do take credit for properly sealing central stack ventilation ductwork. • Prerequisite: 10 CFM50 per floor per shaft • Use duct blaster to pressurize shaft • Take CFM50, and divide by number of floors • If less than 10 per floor, take credit • Add 10 CFM per floor per shaft to design CFM in Baseline • Add measured value to design CFM in Proposed
3.14 Fan Motor Energy • Baseline Building • PTAC/PTHP fan power: 0.3 Watts/CFM • Ex. 400 CFM fan consumes 120 Watts • Other fan power=(bhp x 746)/motor efficiency • Range hoods up to 500 CFM, bathroom and utility fans 90-500 CFM, and in-line ventilating fans: 2.3 CFM/Watt • Bathroom and utility room fans of 10-80 CFM: 1.2 CFM/Watt