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 ForumDecember 7th, 2010

Ben Larson, Ecotope Inc.ben@ecotope.com

Anne Brink, Northwest Energy Efficiency Allianceabrink@nwalliance.org

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 CodeIECC 2009 Z5 + Z6 ID+MT BOP1 ID+MT BOP2 “Montana House”

HVAC Equipment Zonal Resistance Zonal ResistanceFurnace AFUE 80 AFUE 90 AFUE Zonal Electric

ResistanceZonal Electric

ResistanceHeat Pump HSPF / SEER 7.7 / 13 9.0/14.5Envelope

Ceiling R-38 or R-49 R-38 RH R-49 RH R-49 RHWall R-20 R-21 Adv R-21 + R-5 foam R-21 + R-5 foam

Floor R-30 R-30 R-38 R-38Slab R-10, 2-ft or 4-ft 2ft - R-10 R-10 Full R-10 Full

Window U-0.35 U-0.30 U-0.30, SHGC≥0.4 U-0.32Glazing % 16.6% 15% 15% 21%

Infiltration and Ventilation Blower Door Test --- 4ACH50 2.5ACH50 6ACH50

Mechanical Ventilation --- ASHRAE Std 62.2 (Pt Source) HRV 70% Recovery Whole-House system

requiredDHW

Gas EF 0.59 0.62 ---- ----Elec EF 0.9 0.93 0.93 0.93

Low Flow Fixtures ---- x x ----Ducts Sealed Sealed None permitted None permitted

Lights: % CFLs, LPD (W/ft2) 50%, 1.1 80%, 0.72 90%, 0.6 50%, 1.1

BOP2 Package Incremental Cost• BOP2 Incremental Cost over Code Compliant House: $4,501

– Using same costs as presented in August. 2006 $’s. Sources are the 6th Power Plan and existing RTF measures.

• (Cost details follow on next two slides)– Ceiling upgrade to R-49RH: $0.39/ft2, $295– R-5 Wall Sheathing: $0.87/ft2, $1,897– Floor upgrade to R-38: $0.41/ft2, $305– ERV & house tightening: $0.75/ft2, $1,721– Water heater EF upgrade to 0.93: $69– Lighting upgrade: $0.12/ft2, $275

Envelope and Ventilation Cost InputsIncrement Level Base Level

$/ft2 component area or $/item

2006 $sSource

Envelope R-49 RH Ceiling Insulation R-38 RH or R-49 Std $0.39 6th Plan Appendix GR-60 RH Ceiling Insulation R-38 RH or R-49 Std $0.39 6th Plan Appendix GR-21 Adv Frame Wall R-21 Std $0.15 6th Plan Appendix GR-21 Std Wall + R5 Foam Sheathing R-21 Std $0.87 6th Plan Appendix GR-38 Floor R-30 $0.41 6th Plan Appendix GSlab R-10 Full R-10 2' perim $0.81 6th Plan Appendix GWindow U-0.30 U-0.32 $0.00 competitive as base windowWindow U-0.25 U-0.32 $2.00 6th Plan Appendix G

Window U-0.22, SHGC>=0.35 U-0.32 $2.50 RTF Meeting June 2, 2009. Atrium windows.

Air Sealing & Ventilation

Infiltration to 4 ACH50 WA w/BD $295ResWXSF_FY10v2_1.xls, at $.18/ft^2 per 1ACH50 reduction. Then applied to baseline housing stock characteristics.

Infiltration to 4 ACH50 w/ Blower Door Test ID+MT $704ResWXSF_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

ERV None $0.75Modified 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 Level Base Level$/ft2 component area or $/item

2006 $sSource

Domestic Hot Water

Gas Water Heater 0.62 EF 0.59 EF $175

ACEEE Consumer Guide to Home Energy Savings. November 2007. Effhttp://www.aceee.org/consumerguide/waterheating.htm

Elec Water Heater 0.93 EF 0.9 EF $69 6th Plan Appendix G Table G-14

Gas Water Heater 0.82 EF 0.59 EF $700 Current bid prices from Renai and Takagi (ETO RA 2010). BC Hydro has $700, ACEEE has $750.

Heat Pump Water Heater 2 EF 0.9 EF $800 6th Plan Appendix G. Incremental cost over EF 0.9 tank. Table G-14

Low Flow Fixtures Fed 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 Cx None $225 RTF August 2010 MtgFurnace Upgrade to 90AFUE 80 AFUE $300 ETO Resource Assessment 2010Heat Pump Sizing $205 RTF August 2010 MtgHeat Pump HSPF Upgrade to 9.0 7.7 HSPF $1,621 RTF August 2010 MtgHeat Pump HSPF Upgrade to 9.0 8.5 HSPF $63 RTF August 2010 MtgLighting

CFLs - 80% 50% $0.06 6th Plan Appendix G. $/ft^2. Incremental from 50% to 80%.

CFLS - 100% 50% $0.12 6th 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 6th

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)

• Lighting use calculated based on LPD and 1.5hr/day average on time (09/2010 RTF) (http://www.nwcouncil.org/energy/rtf/meetings/2010/09/Lighting%20Hours%20of%20Use.pptx)

• DHW savings based on existing RTF deemed measures for EF upgrades and shower fixture flow reductions (2.5-->1.75gpm)

• 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

Willamette 47.9% 24Zone 1 43.2% 45%

Puget Sound 38.5% 24Inland Empire* 27.1% 8

Zone 2 36.5% 40%Boise/Twin Falls* 41.8% 14Eastern Idaho* 28.3% 9 Zone 3 28.3% 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

1 45% 60%2 40% 55%3 35% 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

City HVAC Type

House Size (ft2)

UA(Btu/hr/F)

Space Heat Required (kWh/yr)

Compressor Energy (kWh/yr)

Auxiliary Energy (kWh/yr)

Space Cooling Required (kWh/yr)

SeattleCentral Heat Pump 2200 421 9145 3025 300 312Ductless Heat Pump 2200 406 8881 1490 3552 116

BoiseCentral Heat Pump 2200 411 11067 4377 1715 1015Ductless Heat Pump 2200 411 11373 2004 5118 344

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 TCOHVAC Equipment DHP & Zonal Resistance DHP & Zonal Resistance

Heat Pump HSPF 10.0 Single Indoor Unit8.5 Double Indoor Unit

10.0 Single Indoor Unit8.5 Double Indoor Unit

EnvelopeCeiling R49 RH R-38 RH

Wall R-21 Adv R-21 AdvFloor R-30 R-30Slab R-10 Full 2ft - R-10

Window U-0.28 SHGC ≥0.33 U-0.30

Glazing % ≤ 21% 15%Infiltration and Ventilation ASHRAE Std 62.2 Compliant

Blower Door Test 4ACH50 4ACH50

Mechanical Ventilation Pt Source <0.5W/cfm

Pt Source <0.5W/cfm

DHW Gas EF 0.62 0.62Elec EF 0.93 0.93

Low Flow Fixtures x xDucts None permitted None permitted

Lights: % CFLs, LPD (W/ft2) 90%, 0.6 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 Spec 2006 $sWA DHP TCO $ 5,159 ID MT DHP TCO $ 4,890

Comparative Package CostsWA 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?