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

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) 2

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 3

UES Analysis Summary 4

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Measure Cost 16

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 17

Intermediate Values & Measure Aggregation Methodology 18

Weightings 19

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

Annual Savings (kWh/yr) 22 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 Eight Interior Tier 1 Measures Four Interior Tier 2 Measures

23 B/C Ratio’s

Results 24

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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. 26

Study Design 27 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.”

Study Design 28 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

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

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 30

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. 31

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Discussion 33

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? 34

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? 35

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 36

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 37

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