Presentation, Discussion, and Decision on Deemed Measures for EnergyStar Homes: Zonal Electric Heat Path (BOP2) for ID and MT Ductless Heat Pump Technical Compliance Option (TCO) Single Family New Construction Regional Technical Forum December 7 th, 2010 Ben Larson, Ecotope Inc. Anne Brink, Northwest Energy Efficiency Alliance
Goals Approval of deemed savings for revised NW EnergyStar for Homes for ID+MT Zonal Heat Path Base case determination and savings approval for ductless heat pump technical compliance option Presentation in two parts: (1)EnergyStar BOP2, Zonal Resistance Heat Path for ID&MT (2) Ductless Heat Pump TCO
EnergyStar for Homes (History) EPA has recently revised the national specification. Now “version 3.” – Effective January 1, 2011 for ID, WA, MT. NW EnergyStar Homes (NWESH) target energy performance 15% better than code – National spec not good enough to meet performance targets in WA so NWESH revised WA Builder Option Packages (BOPs) to stay ahead of code and also adopted amended versions of the national spec for ID and MT to retain NW approach to heat pump commissioning, duct testing, water heating and heat pump HSPF. – OR BOPs were recently revised to stay ahead of 2008 OR code. In August, RTF reviewed and approved savings for – Gas Furnace and Heat Pump houses in Washington (WA BOP1) – Zonal Electric Resistance houses in Washington (WA BOP2) – Gas Furnace and Heat Pump houses in Idaho and Montana (ID+MT BOP1) Today: Zonal Electric Resistance houses in Idaho and Montana (ID+MT BOP2)
Builder Option Packages (BOPs) BOP1 covers gas furnaces and heat pumps (ducted) BOP2 covers zonal, electric resistance heat – EnergyStar requires resistance heat houses to meet or exceed performance of heat pump houses BOPs include domestic hot water system – In this analysis, when space heat source is electric (HP or resistance) an electric water heater is used. Base case building for BOP2 is a code zonal electric resistance house: – IECC 2009 in ID and MT
ID & MT BOP2 EnergyStar Specs State Code IECC 2009 Z5 + Z6 ID+MT BOP1ID+MT BOP2“Montana House” HVAC Equipment Zonal Resistance Furnace AFUE80 AFUE90 AFUE Zonal Electric Resistance Heat Pump HSPF / SEER7.7 / 139.0/14.5 Envelope CeilingR-38 or R-49R-38 RHR-49 RH WallR-20R-21 AdvR-21 + R-5 foam FloorR-30 R-38 SlabR-10, 2-ft or 4-ft2ft - R-10R-10 Full WindowU-0.35U-0.30U-0.30, SHGC≥0.4U-0.32 Glazing %16.6%15% 21% Infiltration and Ventilation Blower Door Test---4ACH502.5ACH506ACH50 Mechanical Ventilation--- ASHRAE Std 62.2 (Pt Source) HRV 70% Recovery Whole-House system required DHW Gas EF Elec EF Low Flow Fixtures----x x DuctsSealed None permitted Lights: % CFLs, LPD (W/ft 2 )50%, 1.180%, %, %, 1.1
BOP2 Package Incremental Cost BOP2 Incremental Cost over Code Compliant House: $4,501 – Using same costs as presented in August $’s. Sources are the 6 th Power Plan and existing RTF measures. (Cost details follow on next two slides) – Ceiling upgrade to R-49RH: $0.39/ft 2, $295 – R-5 Wall Sheathing: $0.87/ft 2, $1,897 – Floor upgrade to R-38: $0.41/ft 2, $305 – ERV & house tightening: $0.75/ft 2, $1,721 – Water heater EF upgrade to 0.93: $69 – Lighting upgrade: $0.12/ft 2, $275
Envelope and Ventilation Cost Inputs Increment LevelBase Level $/ft 2 component area or $/item 2006 $s Source Envelope R-49 RH Ceiling InsulationR-38 RH or R-49 Std$0.396th Plan Appendix G R-60 RH Ceiling InsulationR-38 RH or R-49 Std$0.396th Plan Appendix G R-21 Adv Frame WallR-21 Std$0.156th Plan Appendix G R-21 Std Wall + R5 Foam SheathingR-21 Std$0.876th Plan Appendix G R-38 FloorR-30$0.416th Plan Appendix G Slab R-10 FullR-10 2' perim$0.816th Plan Appendix G Window U-0.30U-0.32$0.00competitive as base window Window U-0.25U-0.32$2.006th Plan Appendix G Window U-0.22, SHGC>=0.35U-0.32$2.50 RTF Meeting June 2, Atrium windows. Air Sealing & Ventilation Infiltration to 4 ACH50WA w/BD$295 ResWXSF_FY10v2_1.xls, at $.18/ft^2 per 1ACH50 reduction. Then applied to baseline housing stock characteristics. Infiltration to 4 ACH50 w/ Blower Door TestID+MT$704 ResWXSF_FY10v2_1.xls, at $.18/ft^2 per 1ACH50 reduction. Then applied to baseline housing stock characteristics. Pt Source Exhaust Fan <0.5W/cfm Exhaust Fan 0.9 W/cfm $50 Supplier catalog survey 2009 to get WhisperGreen over CSJ ERVNone$0.75 Modified 6th Plan Appendix G cost per RTF meeting 8/25/10. $.75/ft^2 to get 0.2 ACH w/HRV
DHW, HVAC, and Lighting Cost Inputs Increment LevelBase Level $/ft 2 component area or $/item 2006 $s Source Domestic Hot Water Gas Water Heater 0.62 EF0.59 EF$175 ACEEE Consumer Guide to Home Energy Savings. November Effhttp:// /waterheating.htm Elec Water Heater 0.93 EF0.9 EF$696th Plan Appendix G Table G-14 Gas Water Heater 0.82 EF0.59 EF$700 Current bid prices from Renai and Takagi (ETO RA 2010). BC Hydro has $700, ACEEE has $750. Heat Pump Water Heater 2 EF0.9 EF$800 6th Plan Appendix G. Incremental cost over EF 0.9 tank. Table G-14 Low Flow FixturesFed Std$0 No incremental cost to get low flow fixtures over code levels HVAC System Ducts Inside $350 6th Plan Appendix G. Incremental cost to place inside. PTCS Heat Pump CxNone$225RTF August 2010 Mtg Furnace Upgrade to 90AFUE80 AFUE$300ETO Resource Assessment 2010 Heat Pump Sizing $205RTF August 2010 Mtg Heat Pump HSPF Upgrade to HSPF$1,621RTF August 2010 Mtg Heat Pump HSPF Upgrade to HSPF$63RTF August 2010 Mtg Lighting CFLs - 80%50%$0.06 6th Plan Appendix G. $/ft^2. Incremental from 50% to 80%. CFLS - 100%50%$0.126th Plan Appendix G. $/ft^2
Energy Use Estimation Approach End uses under consideration form a house package: – Heating, Cooling, Ventilation, Lighting, Water Heating Space heating and cooling use calculated with SEEM using 6 th Plan weightings for prototype size and climate zones. – Savings calculated for all 9 climate zone combinations but not all always apply in each state – Ventilation specs required adjustments to SEEM infiltration and then side engineering calculations to determine energy use – SEEM has been previously calibrated to billing data (11/2009 RTF) SEEM has been previously calibrated to billing data Lighting use calculated based on LPD and 1.5hr/day average on time (09/2010 RTF) ( DHW savings based on existing RTF deemed measures for EF upgrades and shower fixture flow reductions (2.5-->1.75gpm)EF upgradesshower fixture flow reductions
Significant savings because base case is resistance heat code house while BOP2 is resistance heat with thermal envelope set to perform at heat pump energy input levels Savings come almost entirely from heating load reduction although there are some DHW savings as well.
Decision Approve EnergyStar BOP2 for Idaho and Montana deemed savings?
Ductless Heat Pump Technical Compliance Option for EnergyStar in both WA and ID & MT
Overview Technical Compliance Options (TCOs), or component trade- offs, are energy efficiency substitutions within the Northwest Builder Option Package (BOP) prescriptive measures. They are designed to achieve the same level of savings as the standard BOP but often use different heating systems. They may not necessarily be cost effective but are often builder- preferred (ex: hydronic radiant floor). – TCOs approved via technical review committee Savings estimates for new construction from DHPs are sufficiently complicated that they merit review by RTF – Base case: code electric resistance zonal house – DHP savings analysis: fraction of house heated by DHP
Base Case House? Zonal resistance heat or central, ducted heat pump? Proposal: base case house for this measure is a zonal electric resistance code house (using appropriate code for each state) – Houses built with DHPs are still zonally heated and still have large heating load fractions provided by zonal resistance heaters – The DHP is a clear offset to the COP=1 heating sources Net result: using an elec. resistance heat base gives large savings because EnergyStar target house performs 15% better than a code central heat pump house.
DHP Energy Savings % saved over a COP=1 heating system *Zone 2&3 data are only a partial year. Full record will show more savings. Zones 2&3 also have supplemental (wood) heat in the data New construction expected to show more savings because house is better insulated (leads to better internal heat distribution to distant rooms) We also expect savings to decrease in colder climates because the far zones on colder days cannot be heated by a single DHP indoor unit. Proposed NC savings is likely conservative NEEA DHP Pilot Program Evaluation of DHP Retrofits. Interim Data.Proposal: Cluster% saved (Raw) n% saved (Raw) by Heating Zone % saved (adjusted) New Construction Willamette47.9%24 Zone 143.2%45% Puget Sound38.5%24 Inland Empire*27.1%8 Zone 236.5%40% Boise/Twin Falls*41.8%14 Eastern Idaho*28.3%9 Zone 328.3%35%
DHP Energy Use Modeling Use SEEM to simulate house with best heat pump in equipment library Heat pump in SEEM library is not inverter driven but does have ECM fan, HSPF 9 SEER 14.5 SEEM gives us annual heating energy and predicts heat pump performance (leads to an annualized COP) We then adjust the fraction of the heat provided by the DHP and resistance heaters to match the field data As a comparison, central heat pumps heat typical EnergyStar homes with 75%-95% compressor (remainder is auxiliary heat) depending on climate. Heating Zone% heating energy saved % of house heated by DHP 145%60% 240%55% 335%50%
DHP Cooling Take-back Base case house doesn’t have cooling, but DHP does. Cooling analysis assumes same fraction of house is conditioned as in heating (50-60%) DHP cooling equipment efficiency also much higher than central, ducted, split system. – Modeled as SEER 20
Energy Modeling Sample Calcs EnergyStar spec home in Seattle and Boise – Seattle example uses HSPF 8.5, commissioned heat pump with interior ducts – Boise uses HSPF 9, commissioned heat pump with sealed, exterior ducts CityHVAC Type House Size (ft 2 ) UA (Btu/ hr/F) Space Heat Required (kWh/yr) Compressor Energy (kWh/yr) Auxiliary Energy (kWh/yr) Space Cooling Required (kWh/yr) Seattle Central Heat Pump Ductless Heat Pump Boise Central Heat Pump Ductless Heat Pump
WA and ID+MT DHP TCO Specifications Changes from BOP1 spec in blue bold: – In WA, window from U-0.3 to U-0.28 – All lights to high efficacy – Heat pump HSPF to 10 for a single unit. Spec allows for a zonally heated house without substantial envelope upgrades WA DHP TCO ID+MT DHP TCO HVAC Equipment DHP & Zonal Resistance Heat Pump HSPF 10.0 Single Indoor Unit 8.5 Double Indoor Unit 10.0 Single Indoor Unit 8.5 Double Indoor Unit Envelope CeilingR49 RH R-38 RH WallR-21 Adv FloorR-30 SlabR-10 Full 2ft - R-10 Window U-0.28 SHGC ≥0.33 U-0.30 Glazing %≤ 21% 15% Infiltration and VentilationASHRAE Std 62.2 Compliant Blower Door Test4ACH50 Mechanical Ventilation Pt Source <0.5W/cfm DHW Gas EF0.62 Elec EF0.93 Low Flow Fixturesx x DuctsNone permitted Lights: % CFLs, LPD (W/ft 2 )90%, 0.6
DHP TCO Package Costs (2006 $s) Single unit DHP: $3,899 – NEEA pilot program database, n=2412 Also subtract cost of 4 baseboard heaters at $125 ea (Means contractor pricing 2005). Total equipment upgrade cost: $3,399 EnergyStar Spec2006 $s WA DHP TCO $ 5,159 ID MT DHP TCO $ 4,890 Comparative Package Costs WA BOP1 Ducts Inside, Heat Pump $ 1,724 ID & MT EnergyStar, Heat Pump $ 3,404 WA BOP2, Electric Zonal$ 5,270 ID MT BOP2, Electric Zonal$ 4,501
Decision Approve EnergyStar Ductless Heat Pump Technical Compliance Option Savings Estimate for New Construction in Washington, Idaho, and Montana?