Heat Pump Water Heaters

1. Heat Pump Water Heaters Provisional UES Proposal Regional Technical Forum October 4th, 2011

2. Introduction • More time for discussion today than at the last meeting • Decision today? • We’ll see how it goes. • What changed from last meeting • 45 gal/day • (was 40 gal/day for small tank and 60 gal/day for large tank) • Aggregated many measures (from 108 to 15 measures) • Tank size definitions • Small: 50 to 75 gallons • (was 55 gal or less) • Large: more than 75 gallons • (was greater than 55 gal) • Other more minor changes (we’ll point them out)

3. Measure Summary • Measure name: Heat Pump Water Heater • Measure description • Installation of a heat pump water heater instead of a standard electric tank water heater in single family site built homes. • Measure type: UES • Today’s Request: Discussion, Review, (Decision???) • Change in measure status: Proposed Provisional • Change in measure savings: n/a • Change in measure cost effectiveness: n/a • Other or follow-on work for RTF: Tier 2 interior

4. UES Analysis Summary

16. Measure Cost

17. Measure Life • 15 years • Same as standard RTF water heater measures. • Northern Climate Specification warranty requirements: • Tier 1: 6 years (Energy Star) • Tier 2: 10 years

18. Intermediate Values & Measure Aggregation Methodology

19. Weightings

21. Note: These values do not take into account space heat interaction.

22. Eight Interior Tier 1 Measures • Annual Savings (kWh/yr) One Unheated Buffer Space, Small Tank, Tier 1 Measure One Unheated Buffer Space, Large Tank, Tier 1 Measure One Unheated Buffer Space Tier 2 Measure Four Interior Tier 2 Measures

23. B/C Ratio’s

24. Results

26. Plans for Additional UES’s • Tier 2, Interior, with required Exhaust Duct • Plan to model within revised version of SEEM • New SEEM model (available this month) will perform a more detailed hourly simulation of whole house infiltration • This will include the ability to input exhaust fan schedules.

27. Study Design From the Guidelines, for provisional UES status: “A study design has been developed that is likely to result in data on efficient-case energy consumption that will support RTF approval for active UES values.”

28. Study Design • Goal: Collect data useful in determining the next iteration of provisional UES for heat pump water heater measures. • Intentionally straying from Guidelines’ purpose of provisional data collection due to: • measure’s potential importance to the Region • expected evolution of HPWH technology over the next few years • Three primary data collection areas • Hot Water Consumption • Space Conditioning Interaction (model inputs) • In-field COP • Study Dates • Site/Participant recruitment • Program participants through 3/31/2013 • Overlap of site selection across data collection areas expected • Study data collection period: 6/1/2013 – 5/31/2014 • Installation of monitoring equipment would occur well before 6/1/2013 • Provisional UES Sunset Date: 12/31/2014

29. Study Area: Hot Water Consumption • Data Collected • Monthly hot water consumption (gallons) • Sample • 200 sites • Random/representative sample of program participants

30. Study Area: Space Heat Interaction • Data Collected • Unheated Buffer Space-to-House UA • Unheated Buffer Space estimate of internal gains (equipment audit) • Sample • 50 sites

31. Study Area: In-Field COP • Data Collected • Hot water consumption (gallons) • Unheated Buffer Space-to-House UA • Unheated Buffer Space estimate of internal gains (equipment audit) • HPWH energy consumption • Compressor and Fan • Electric resistance • ΔT of water delivered • Ambient temperature • For tier 2 (assumes constant speed fan): • Two-time measurement of • airflow • incoming air temperature • Sample • 75 sites • Site selections weighted by program occurrence of HPWH model, installation location, and heating zone.

33. Discussion

34. Open Issues (1) • Baseline Energy Use Reliability • RCDP cycle 2 data too old? (from early 1990’s) • Is the 2.5 people/house assumption reliable? • Applying 45 gpd to both tank sizes • Will it “reliably” represent the future program participants?

35. Open Issues (2) • Study Design • Adequate Study Areas? • Sample sizes? • Need input/statistics applied • Operating modes – will study design capture the “average” operating mode? • Length of study • Need a Control Group?

36. Open Issues (3) • Analysis Approach • Gallons Per Day versus Household Size • Current proposal does not distinguish between household size. • Gallons Per Day versus ODT • Current proposal assumes the same volume of water every day of the year. • RCDP (kWh/month) and EPRI (gal/month) data show significant variation by month; DOE TSD shows significant variation by season. • Study Design allows future analysis to vary gal/day by outdoor temperature. • Space Heat Interaction

37. Open Issues (4) • Sunset Date • 12/31/2014 • Expected timing for study results and analysis completion • Also • New/revised equipment expected • New Federal Standard effective April 16, 2015 • Measure Life

38. IF there were to be a motion today, it MIGHT look something like this: “I _________ move that the RTF approvethe UES for Heat Pump Water Heaters under provisional status with a sunset date of December 31st, 2014.” (Tier 2 interior location heat pump water heaters will be pursued/added at a later date.)