Residential Heat Pump Water Heaters UES Measure Update Proposal Regional Technical Forum November 18, 2014

Presentation Outline Measure Overview and Context Summary of Provisional Measure and Research Subcommittee Summary Measure Savings, Cost, Life, TRC B/C Proposed Decision 2

Measure Overview 3 Measure DevelopersEcotope, NEEA, BPA Contract Analyst ReviewYes (Christian Douglass, Adam Hadley) Technical Subcommittee ReviewYes Research & Evaluation Subcommittee Review Not yet

Context 55% of 4 million households in PNW have electric water heaters (2011 RBSA SF Survey) 2.7 people in a house use 3,380 kWh/yr on site (2014 RBSA Metering Study) 3.38 MWh/yr x 2.2 million households / 8760 hrs/yr = 850 aMW of site electricity HPWHs have roughly an annual COP of 2 Site electric savings potential = 425 aMW 4

Provisional Measure Summary 5 Approved as Provisional UES on October 4, 2011 (Tier 2 ducted approved February 14, 2012) The measures cross the entire PNW and are not separated by climate zone Annual Energy Saving (kWh/yr)Tier 1Tier 2 HPWH LocationSpace Heat Type Small Tank Large TankAny Size Unheated Buffer LocationAny Heat Type 887 1,817 1,794 Interior Location Gas Heated 1,547 2,169 1,724 Interior Location Zonal Electric Heated Interior Location Electric Furnace Heated Interior Location Heat Pump Heated 1,189 1,686 1,243

Research Plan (October 4, 2011) 6

Regional HPWH Research Field Studies 1.“NEEA Heat Pump Water heater Field Study Report.” Fluid Market Strategies, for NEEA. October 22, 2013.“NEEA Heat Pump Water heater Field Study Report.” Fluid Market Strategies, for NEEA. October 22, “Heat Pump Water Heater Model Validation Study” DRAFT REPORT. Ecotope, for NEEA. July 28, Lab Coefficient of Performance (COP) Tests 1.Larson, B. and M. Logsdon. “Laboratory Assessment of Sanden GES-15QTA Heat Pump Water Heater.” Ecotope for NEEA. Nov 6, 2013.Larson, B. and M. Logsdon. “Laboratory Assessment of Sanden GES-15QTA Heat Pump Water Heater.” Ecotope for NEEA. Nov 6, Larson, B., and Logsdon, M. February Laboratory Assessment of AO Smith Voltex Hybrid Heat Pump Water Heater. Prepared for the Northwest Energy Efficiency Alliance. Retrieved from: 3.Larson, B., and Logsdon, M. February 22, Laboratory Assessment of AirGenerate ATI66 Hybrid Heat Pump Water Heater. Prepared for the Northwest Energy Efficiency Alliance. Retrieved from: 4.Larson, B., and Logsdon, M. September Laboratory Assessment of General Electric GeoSpring Hybrid Heat Pump Water Heater. Prepared for the Northwest Energy Efficiency Alliance. Retrieved from: 5.Larson, B. March Laboratory Assessment of AirGenerate ATI80 Hybrid Heat Pump Water Heater. Prepared for the Northwest Energy Efficiency Alliance. Retrieved from: 6.Larson, B. June Laboratory Assessment of Rheem HB50RH Heat Pump Water Heater. Prepared for the Northwest Energy Efficiency Alliance. Retrieved from: Larson, B., and Logsdon, M. August Laboratory Assessment of AO Smith SHPT-50 Heat Pump Water Heater. Retrieved from: Space Heat Interaction Studies 1.Widder SH, JM Petersen, GB Parker, and MC Baechler. July Impact of Ducting on Heat Pump Water Heater Space Conditioning Energy Use and Comfort. PNNL-23526, Pacific Northwest National Laboratory, Richland, WA. 7

RTF Research Plan & Outcomes lations_Provisional_Proposal_021412_v5.pptx lations_Provisional_Proposal_021412_v5.pptx 8 Study AreaResearch OutcomeStatus Hot Water Consumption 100+ Households successfully metered. Draw profiles created for 1, 2, 3, 4, & 5+ occupancy households In-field COP 100+ Households successfully metered. Inlet & outlet water temperature. Ambient air temperature. Water heater energy use. Space Conditioning Interaction (non- ducted and exhaust ducted units) Indeterminate

Summary of Research Outcomes, By Parameter 9 ParameterExistingProposed Tank Setpoint~122.5°F128°F Inlet Water Temperature Assumed constant ~50°FVaries throughout the year and based on water source Hot Water Consumption 45 gal/day with no draw schedule 40 gal/day average. Independent draw schedules for 1, 2, 3, 4, & 5+ person households Ambient Space Temperatures Estimates with “loosely” calibrated simulations Calculated based on model fits to observed data Heating System Interaction 100%65% (subcommittee judgment) HPWH EfficienciesBased on lab testsBased on lab Tests and calibrated to field data Model CalibrationUncalibratedCalibrated

Subcommittee Summary: Dates & Attendees October 21, 2014 (2 hours) Link to Presentation Link to Meeting Notes Attendees: Jennifer Anziano Christian Douglass Ben Larson Robert Weber Aaron Winer David Thompson Josh Rushton Andie Baker Rick Knori Brad Acker November 6, 2014 (1.5+ hours) Link to Presentation Link to Meeting Notes Attendees: Jennifer Anziano Christian Douglass Ben Larson Robert Webber Aaron Winer David Thompson Josh Rushton Andie Baker Mark Johnson Dave Kresta Sarah Widder Kevin Price Jeff Harris Kevin Watier Adam Hadley 10

Subcommittee Summary: Consensus on Specifics Model calibration (10/21) – The HPWH model developed within SEEM is sufficiently calibrated for the purposes of estimating a UES. How to treat the impending federal water heater standard (10/21) – Assume the federal standard goes into effect now (instead of April 2015). The staff resources to develop multiple measure sets is not worth the effort and could be cumbersome for programs. Whether to have an "any size" tank measure or separate small/large tank measures (10/21) – An "any size" measure based on the weighting of small and large tanks in the region is appropriate. A relatively short sunset date (~1 year) should be used to monitor market shifts in average tank size. 11

Subcommittee Summary: Consensus on Specifics (continued) Valuing self-install labor at zero cost (10/21) – Defer this discussion to the broader RTF, since it relates to the Guidelines and many measures in addition to HPWH. HVAC interaction for interior installations (11/6) – Provisionally assume a heating interaction factor of HC f = 65% for exhaust ducted and non-ducted. – Pursue a dual research plan using a.) the PNNL lab homes and b.) a “paper study” which looks at the correlation between temperature depression and HC f. Baseline for large tanks impacted by federal standard (11/ /14 over ) – Collecting data on existing tank size is appropriate – An additional or supplemental survey may be used to elicit baseline information Where to include houses with DHPs (11/ /14 over ) – Bundle DHPs with Heat Pumps in the measure identifier 12

HVAC Interaction Factor Research Options Considered Option 1: Additional study using PNNL lab homes (~$100k) – Will help provide a better understanding of the range of interaction factors by testing four more HPWH locations throughout the lab home Option 2: “Paper study” (~$10k) – Low cost option using existing data and models to help bound interaction factor Option 3: Large scale, “flip-flop” field research study (~$1M) – The most comprehensive study, it would provide a direct output of the factor of interest – Is such an expensive study worth it? Yes, because HPWH is a huge resource (~400 aMW) and our current uncertainty causes savings to vary by +/- 20%? Subcommittee recommends developing a research plan combining Options 1 and 2 – Why? Options 1 and 2 are relatively low cost, yet they may bound the factor to an acceptable level – If this turns out not to be the case, Option 3 is still on the table 13

Proposed Measure Summary measure applications Measures identified by tank location, HVAC type, efficiency, and exhaust ducting (yes/no) (note: tank size not a proposed identifier at this time) HZ1 Location / HVAC TypeTier 1Tier 2Tier 2 Ducted Interior Gas 1,231 1,309 1,218 Interior EFAF Interior HP 1,089 1,134 1,047 Interior Zonal Garage 1,016 1,220N/A Basement 1,116 1,223N/A HZ2 Location / HVAC TypeTier 1Tier 2Tier 2 Ducted Interior Gas 1,297 1,376 1,281 Interior EFAF 982 1, Interior HP 1,114 1,156 1,045 Interior Zonal 1,018 1, Garage 847 1,252N/A Basement 1,155 1,267N/A HZ3 Location / HVAC Type Tier 1Tier 2 Tier 2 Ducted Interior Gas 1,328 1,436 1,337 Interior EFAF 1,040 1, Interior HP 1,143 1,208 1,059 Interior Zonal 1,074 1, Garage 708 1,287N/A Basement 1,161 1,314N/A

Measure Savings 15 Heating Zone 1 Gar. = Garage, Base. = Basement

Measure Savings (continued) 16 Heating Zone 2 Gar. = Garage, Base. = Basement

Measure Savings (continued) 17 Heating Zone 3 Gar. = Garage, Base. = Basement

Cost & Life 18 Measure life – Existing: 15 yrs (Source: ??) – Proposed: 13 yrs (2009 DOE TSD)TSD Incremental Cost

TRC B/C Ratios 19 Heating SystemLocationTier Climate Zone HZ1HZ2HZ3 Any Garage Tier Tier Basement Tier11.8 Tier Zonal Electric Resistance Interior Tier Tier Ducted Tier20.4 Electric Furnace Interior Tier Tier Ducted Tier20.4 Heat Pump Interior Tier11.6 Tier20.7 Ducted Tier20.5 Gas Furnace Interior Tier Tier Ducted Tier20.6

Proposed Decision “I ______ move the RTF: Update the savings, cost, and life for the HPWH UES measures as proposed and set the measure to Provisional category and Under Review status Direct staff to develop research plan focused on: 1.HVAC interaction factor, using a combination of a PNNL lab homes study and a paper study, as proposed; and 2.Determining baseline for large tanks (>55 gal), using data on existing tank size and possibly survey data. Set the sunset date to 4/2015, at which time the RTF will review the proposed research plan, and if approved, set the measure to Active status.” 20

Backup Slides 21

Heating System Interaction Applies only to interior ducted or non-ducted installations (i.e. garage and unconditioned basement installs are excluded from this discussion) Heat pump water heaters extract heat from the space where they are installed. Some of that heat energy is replaced by the heating system. We have observed that not every unit of energy removed from the air by the HPWH is replaced by the heating system 22 Electric Storage Tank Water Heaters LocationOveralln Basement29%240 Main House44%361 Garage19%155 Crawl4%31 Other3%27 Is the WH Space Location Conditioned? LocationNoYes Basement16%84% Main House5%95% Garage92%8% Crawl86%14% Other75%25% Overall30%70% Source: RBSA

23 HVAC System Interaction = m*c p *ΔT + Q UA Typical air Δ T at 68  F entering air: ~15  F Warm House Air Cool HPWH Exhaust Air Tank Heat Losses Conditioned Space Installation Heat Flows

24 HVAC System Interaction = m*c p *ΔT + Q UA Δ T now depends on outside air T m now depends on added infiltration load Warm House Air Cool HPWH Exhaust Air Tank Heat Losses Ducted to Outside, Conditioned Space Heat Flows Added Infiltration Load

Available Studies Field study of HPWH interaction factors was inconclusive What we know from PNNL Lab Homes Study 1 – Interaction factor for interior HPWH installations ≈ 49% – Interaction factor for ducted HPWH installations ≈ 44% – Study looked at one installation of a HPWH in a closet next to an exterior wall 25 1 PNNL. Impact of Ducting on Heat Pump Water Heater Space Conditioning Energy Use and Comfort. July 2014.Impact of Ducting on Heat Pump Water Heater Space Conditioning Energy Use and Comfort

PNNL Study – Water Heater Location PNNL. Impact of Ducting on Heat Pump Water Heater Space Conditioning Energy Use and Comfort. July 2014.Impact of Ducting on Heat Pump Water Heater Space Conditioning Energy Use and Comfort 26

Logic Behind 65% Heating Interaction Assumption 27 Subcommittee agreed that HVAC factor would differ for heated basements versus more central, “main house” locations Assume HVAC factor of 50% for heated basements, 75% for main house Weight these by RBSA saturation for electric tank locations (basement %, main house – 63.2%) Weighted average ≈ 65%