Predicted Savings for NW Energy Star for Homes and WA BuiltGreen Homes

Specification UpdateSingle Family New Construction

Regional Technical ForumAugust 25th, 2010

Ben Larson, Ecotope Inc.ben@ecotope.com

Anne Brink, Northwest Energy Efficiency Allianceabrink@nwalliance.org

Goal• Approval of deemed savings for revised NW

EnergyStar for Homes and WA BuiltGreen Programs

• Presentation in two parts:(1) EnergyStar for Washington, Idaho, and Montana(2) BuiltGreen for Washington

Analysis 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• Lighting use calculated based on LPD and 1.5hr/day average

on time• DHW savings based on existing RTF deemed measures for EF

upgrades and shower fixture flow reductions• Costs taken from 6th Plan and existing RTF measures

EnergyStar for Homes• EPA has recently revised the national specification. Now “version 3.”

– Effective January 1, 2011 for ID, WA, MT.• WA energy code has also recently been updated.

– Effective date: January 1, 2011• NW EnergyStar Homes (NWESH) target energy performance 15% better than

code– National spec not good enough to meet performance targets in WA– NWESH revising WA Builder Option Packages (BOPs) to stay ahead of

code. – OR BOPs were recently revised to stay ahead of 2008 OR code. (not

discussed further in this presentation)– ID and MT programs will go to national envelope spec while retaining

existing NW approach to heat pump commissioning, duct testing, water heating and heat pump HSPF.

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 gas, a gas water

heater is used. When space heat source is electric (HP or resistance) an electric water heater is used.

WA Code 2009 Baseline• WA 2009 Code compliance met through the choice

of several options. (Table 9-1 in code)• For this analysis, the HVAC efficiency upgrade (option

1) was selected for the forced air paths. For the zonal resistance path, improved shell and efficient water heating were chosen (options 3a and 5a). – These then sets the performance target that the

EnergyStar homes beat by 15%.– This also effects the total package incremental cost

because the options selected are now in the baseline

• If the house uses other code compliance options, savings will be greater than those in this analysis

WA BOPs 1 & 2

• BOP1 requires one of three additional measures:• Env - Envelope upgrade to R-21 Std + R5 foam wall & U-0.25, SHGC≥0.30 windows• Duc - Ducts inside• DHW - DHW equipment to 0.82 EF gas or 2.0 EF electric, furnace to 94AFUE

WA 2009 Code Nat’l EStar WA BOP1 WABOP2HVAC Equipment Forced Air Path Zonal Resistance EStar HP efficiency varies by IECC Climate Zonal Resistance

Furnace AFUE 92 Zonal Electric Resistance

90 92 Zonal Electric ResistanceHeat Pump HSPF / SEER 8.5 / 13 8.5/14.5 or 9.25/14.5 8.5/14.5 or 9.0/14.5

Envelope All envelope measures can be met with equivalent UA Ceiling R-38 RH R-38 RH R-38 RH R49 RH R-60 RH

Wall R-21 R-21 R-21 Adv R21 Adv R-21 Std + R5 FoamFloor R-30 R-38 RH R-30 R-30 R-38Slab 2ft - R-10 R-10 Full 2ft - R-10 R-10 Full R-10 Full

Window U-0.32 U-0.28 U-0.30 U-0.30 SHGC ≥0.35

U-0.22 SHGC ≥0.35

Glazing % 16.6% 16.6% 15% ≤ 21% ≤ 21%Infiltration and Ventilation ASHRAE Std 62.2 Compliant

Blower Door Test 6ACH50 6ACH50 4ACH50 4ACH50 2.5 ACH 50

Mechanical Ventilation Furnace Fan Pt Source Furnace Fan Pt Source <0.5W/cfm HRV 70% Recovery

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

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

Lights: % CFLs, LPD (W/ft2) 50%, 1.1 50%, 1.1 80%, 0.72 80%, 0.72 100%, 0.6

WA BOP Spec Details• Low flow fixtures:

– 1.75gpm showers and kitchen sinks, 1.0gpm lavs. – Savings only claimed for 2 showerheads per RTF 2/2010

• Water heater EF ratings for upgraded DHW:– Savings per RTF for resistance tank upgrades:– HPWH specified at 2.0 EF but modeled at 1.5 EF.

• HPWH will be installed in garages. Tave in garage lower than EF rating point so we expect lower performance. 1.5 EF meant to be a conservative estimate. Actual performance may be better or worse.

• Ventilation:– Base case assumes furnace blower with intentional return leak used 8 hrs/day – BOP specifies high efficiency (<0.5 W/cfm) exhaust fan on timer operating one

out of every two hours (ASHRAE 62.2 compliant)

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

Package Cost Summary

Energy Star Gas Heat Heat PumpWA BOP1 Envelope $ 3,468 $ 3,791 WA BOP1 Ducts Inside $ 1,401 $ 1,724 WA BOP1 DHW $ 1,576 $ 2,106 WA BOP1 Average $ 1,884 $ 2,214 ID & MT EnergyStar $ 2,059 $ 3,404

Zonal ResistanceWA BOP2 $ 5,270 BG3 Star Window $ 865 BG3 Star Ceiling $ 728 BG3 Star Wall $ 2,025 BG3 Star Average $ 872 BG4 Star $ 3,243 BG5 Star $ 4,914

BuiltGreen Gas Heat Heat Pump3 Star $ 363 $ 256 4 Star same as WA BOP15 Star Wall $ 3,440 $ 3,590 5 Star Window $ 2,083 $ 2,233 5 Star Average $ 2,355 $ 2,504

WA BOP Savings SourcesBOP1 Gas House (most measures are heating or dhw but some electric savings

sources exist):

– Lights: LPD 1.10.72 W/ft2

– Ventilation system changed from furnace blower to point-source exhaust

• Extra blower runtime for ventilation use decreases as heat load (and run time) increases so savings decrease for this in colder climates

• BOP1 Heat Pump House:– LPD 1.10.72 W/ft2

– Ventilation system changed from furnace blower to point-source exhaust

– Heat load reduction from decreased UA– DHW use reduction from low flow fixtures and higher EF

WA BOP1 Compliance Options• BOP1 has three compliance options: envelope upgrades,

interior ducts, or DHW tank upgrades• Each produce a generally similar level of savings (by design)

but costs vary between options especially regarding the envelope.

• A possibility of creating a weighted average of the options exists but we have to estimate distribution of each option. – Advantages: simplifies entries in PTR and deems single BOP1 #– Weights used in “BOP1 ave” on next 2 graphs

• Decision: approve weighting approach, modify or discard?

Gas Heat Heat Pump

Envelope 0.2 0.2

Ducts 0.4 0.6

DHW 0.4 0.2

• BOP2 houses have no cooling system so savings calculated for heating zones only

• Savings Sources:– LPD 1.10.6 W/ft2

– Heat load reduction from decreased UA (both insulation and infiltration improvements). Substantial because EnergyStar target is performance equivalent to WA Code heat pump house but these savings are for WA Code zonal electric house.

– No DHW savings because this is assumed in the base case for code compliance (WA Code 2009 Option 5a).

ID & MT EnergyStar Specs

– ID and MT programs build on the national spec to include:• DHW improvements

and retain • PTCS heat pump

commissioning, • duct testing, and • NW heat pump HSPF.

– National spec starts glazing at 15%. If % increases, reductions in window U-value are required.

IECC 2009 Z5 + Z6 Adjusted Nat’l EStarHVAC Equipment

Furnace AFUE 80 AFUE 90 AFUEHeat Pump HSPF / SEER 7.7 / 13 9.0/14.5

Envelope Ceiling R-38 or R-49 R-38 RH

Wall R-20 R-21 AdvFloor R-30 R-30Slab R-10, 2-ft or 4-ft 2ft - R-10

Window U-0.35 U-0.30Glazing % 16.6% 15%

Infiltration and Ventilation Blower Door Test --- 4ACH50

Mechanical Ventilation --- ASHRAE Std 62.2 (Pt Source)

DHW Gas EF 0.59 0.62Elec EF 0.9 0.93

Low Flow Fixtures ---- ----Ducts Sealed Sealed

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

ID+MT Energy Star Savings Sources• Gas House:

– LPD 1.10.72 W/ft2

– Cooling use reduction through higher SEER and better glazing (also lighting interaction benefit)

– No ventilation system benefit

• Heat Pump House:– LPD 1.10.72 W/ft2

– Heat load reduction from decreased UA– DHW use reduction from low flow fixtures and higher EF– Cooling use reduction through higher SEER and better glazing (also

lighting interaction benefit)– No ventilation system benefit

WA Built GreenSpecs (forced air)• Glazing allowed up to 21% of CFA• (3 Star)

– State Code Plus:• LPD of 0.72 W/ft2• <0.5 W/cfm exhaust fan operating one of every two hours (ASHRAE 62.2 compliant)• 0.62 EF gas or 0.93 electric water heater with reduced flow fixtures:

• (4 Star)– EnergyStar prescriptive insulation levels, equipment standards, and PTCS requirements

but doesn’t require other, non-energy, EnergyStar checklists

• (5 Star)– 4 Star / EnergyStar plus:

• Ducts Inside• HVAC Equipment: Furnace AFUE 94, Heat Pump HSPF 9 / SEER 14.5• Windows to U-0.25 -or- Walls to R-21 Adv with R-5 Foam

• Weights for averaging 5 Star package: Window 0.8 and Wall 0.2• Decision: approve this weighting approach, modify or discard?

BuiltGreen Forced Air Savings Sources• (3 Star)

– LPD 1.10.72 W/ft2– Cooling-lighting interaction benefit– Ventilation system changed from furnace blower to point-source

exhaust– DHW savings through lower flow fixtures and improved tank EF (heat

pump house)• (4 Star) - Same as EnergyStar BOP1• (5 Star)

– Assumes EnergyStar compliance met through ducts inside path– Additional savings over 4 star level through reduced UA (heating and

cooling benefit) ,reduced blower runtime, and increased HVAC equipment efficiency.

WA Built Green Specs (ER zonal)• Glazing allowed up to 21% CFA• (3 Star)

– State Code Plus:• LPD of 0.72 W/ft2

• <0.5 W/cfm exhaust fan operating one of every two hours (ASHRAE 62.2 compliant)• 0.93 electric water heater with reduced flow fixtures:

– 1.75gpm showers and kitchen sinks, 1.0gpm lavs and EStar dishwasher

• Window U-0.28 and two of four additional envelope measures:– R-38 Floor / Slab R-10 Full – Ceiling R-60RH– Wall R-21 Intermediate Framing with R-3 sheathing– Window U-0.25, SHGC>0.35

• (4 Star), unlike forced air path, not EnergyStar equivalent

– 3 Star with all four envelope measures• (5 Star)

– 4 Star plus: HRV at 70% efficiency with infiltration to 2.5ACH50

• Weights for averaging 3 Star package: Window 0.1, Ceiling 0.8, Wall 0.1• Decision: approve this weighting approach, modify or discard?

Built Green Savings Sources (ER zonal)

• (3 Star)– LPD 1.10.72 W/ft2– Decreased UA through improved shell– No DHW savings because they are in the base case

• (4 Star)– Further decreased UA through improved shell

• (5 Star)– Still further decreased UA through improved shell and significant

infiltration reduction

• No cooling system in house so savings calculated for heating zones only

• No cooling system in house so savings calculated for heating zones only

Decision – Approve Savings

• EnergyStar WA BOP1 and BOP2?• EnergyStar ID and MT?• BuiltGreen WA?