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Deemed Savings for Hot Water Savings Measures in Multifamily

Buildings

Showerheads

Faucet Aerators

Pipe Wrap

Tank Wrap

Low Flow Showerheads & Aerators• Current Savings Assumptions

– Showerhead = 158 kWh/yr– Aerators = 0 kWh/yr – 3 year measure life

• Seattle Apartment/Condominium Program– Over 65,000 units had showerheads & aerator– Sub-metered water use in 93 units in 7 buildings

• Showerhead user flow rate pre- 2.3 gpm• Showerhead user flow rate post- 1.6 gpm

– Savings = 200 kWh/yr

• Hot faucet use/day pre- 15.5 gal• Hot faucet use/day post- 8.4 gal

– Savings = 90 kWh/yr (kitchen)– Savings = 80 kWh/yr (bathroom)

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Low Flow Showerhead & Aerator Issues

• EPAC 1992 set maximum showerhead flow rate at 2.5 gpm and faucet aerator flow rate at 2.75 gpm. Oregon and Washington Code required these beginning in 1989/91. – Therefore, if a consumer replaces there showerhead, it must use 2.5 gpm or less.

This means “expected measure life” of incremental savings is shorter.

• Median expected life of showerheads is between 7 – 12 years.– This means that at least 50% of the showerheads already use 2.5 gpm or less.

• Seattle study indicated average “user” showerhead flow rate of 2.3 gpm.– This means that 2.0 gpm or less showerheads are required on average to produce

savings.

• AWWA Research Foundation (1999) showed end-use metering of almost 1200 homes indicated average faucet flow rate of 1.35 gpm.– This means that 1.0 gpm or less faucet are required on average to produce

savings.

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Kitchen and Bathroom Faucet Aerators

• Other Historical Savings Assumptions– PacifiCorp (Single Family)

• One Kitchen + One Bath – 100 kWh, de-rated to 73 kWh/yr for persistence

– PSE• One Kitchen + One Bath = 150 kWh

– PGE • Kitchen – 32 kWh/yr• Bath – 21 kWh/yr

– SCL• Bath – 35 kWh/yr

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Kitchen and Bathroom Faucet Aerators – Summary of Field Research

• AWWA Research Foundation (Approx. 1200 homes, sub-metered fixtures in 1999)– 10.9 gals/day/capita over 8.1 minutes/day/capita– 1.35 gpm average flow rate

• Seattle Water Department (2000) – Single Family– Retrofitted 60 bathroom faucets w/ 1.5 gpm aerators and 27

kitchen faucets w/ 2.2 gpm aerators– Total water use decreased from 9.2 gals/day/capita to 8.0

gals/day/capita. Reduction was statistically significant.– Hot water use was also reduced, but reduction was not

statistically significant.

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Kitchen and Bathroom Faucet Aerators Deemed Savings Options

• Option 1 – Do not accept savings from aerators unless they are documented using RTF Savings Estimation Protocols

• Option 2 – Establish deemed savings value for aerators for multifamily buildings based on SCL/PSE/BPA research

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Hot Water Heater Tank Wrap

• Current Status – Eligible measure, no deemed value• BPA Research (Biemer,Auburg &Ek)

– 190 kWh/yr savings for wrapping EF86 Tank w/R11– 152 kWh/yr adjusted for space heating interaction

• Cost $12 for wrap, $15 for installation• Credit @

– 5 yrs = $18– 7 yrs = $25– 10 yrs = $34

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Hot Water Heater Tank Wrap - Options

• Option 1 – Maintain eligibility, but do not establish deemed savings

• Option 2 – Establish deemed savings based on R11 wrap of EF86 tank with measure life of ? years.