Heat Pump Water Heaters: Tier 2 – Ducted Interior Installations

1. Heat Pump Water Heaters: Tier 2 – Ducted Interior Installations Provisional UES Proposal Regional Technical Forum February 14th, 2012

2. Background • In October 2011, Provisional UES approved for heat pump water heater (HPWH) for: • Northern Climate Specification Tier 1 • Buffer space installs • Interior (non-ducted installs) • Northern Climate Spec Tier 2 • Buffer space installs • Northern Climate Spec Tier 2 Interior Installations require exhaust ducting • Left as “TBD” in October • Presented preliminary analysis in December 2011

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 in an interior location with exhaust ducts • Installation shall comply with the Northern Climate Heat Pump Specification for Tier 2 units with exhaust ducting • Measure spec under development • 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

9. Tier 2: Field Installs • Current NEEA field study specifies interior installs with exhaust ducting limit airflow to 200 cfm • Example from one site (1/27/12): • airflow measurements with 12-point duct traverse

10. Measured Airflow Variation Effects: ATI • NEEA lab testing of ATI at 67.5F ambient • 375 cfm: full flow, capacity and COP • 200 cfm: 5% capacity and 10% COP reduction • 150 cfm: 11% capacity and 12% COP reduction

11. Measured Airflow Variation Effects: Voltex • BPA HPWH lab evaluation observed Voltex compressor performance for 3 flow scenarios at 67.5F ambient temperature • Full flow: 475 cfm • ⅓ filter area blocked: 372 cfm • ⅔ filter area blocked: 284 cfm  Similar, small changes in performance as found with ATI but flow down to 200cfm not tested

12. Overall Savings Estimates • Impact on house heating + cooling system depends on climate, exhaust airflow, and HVAC system type • Combining DHW energy savings with heating + cooling impact produces the overall energy savings estimate • 5 scenarios in 4 climates considered on next slide: • Interior non-ducted (0 cfm flow to outside) • 4 levels of exhaust ducting to outside • 150, 200, 250, and 300 cfm

13. Heating System Interaction • CFM is airflow ducted to outside (“0” corresponds to no ducting) • Negative values are a heating system debit

14. Cooling System Interaction • None for houses without cooling system (Zonal Resistance and Electric Furnace) • Cooling savings for ducted installations nearly negligible but not so for nonducted ones • CFM is airflow ducted to outside (“0” corresponds to no ducting) • Positive values are a cooling system benefit

15. Analysis Outputs: Savings Estimates DHW Savings Combined with Heat+Cool Interaction

16. Analysis Outputs: Combined Savings Tables

17. Measure Cost and Life • Exhaust venting adder includes materials, labor, and concealing cost (wall board repair) http://www1.eere.energy.gov/buildings/appliance_standards/residential/pdfs/htgp_finalrule_app8a.pdf • Total Incremental Cost: $1,810 in 2011 $’s ($1,615 in 2006 $’s) • Measure Life: 15 years – same as other RTF HPWH and WH measures Tier 2 Items

18. Results with B/C Ratios

19. Call for Participants:Regional HPWH Evaluation Advisory Committee • Scope • RTF sub-committee to study savings, AND • regional process and market evaluation • Co-chaired by • RTF (Tom Eckman), and • NEEA (Dave Kresta) • Kick-off meeting by end of Feb • Anticipate bi-weekly meetings for several months, then monthly • Contact Dave Kresta (dkresta@neea.org) if interested in participating by Feb 17th

20. Study Design • Lab tests of Voltex at 200 cfm to confirm performance estimates • Same study design as for other HPWH – here’s the review: • 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

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

22. 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

23. 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.

24. Measure Checklist

25. Discussion • Installation specification • Installations with larger airflows?

26. Motion to Adopt “I _________ move that the RTF approvethe addition of Tier 2, Ducted Interior Installations to the UES for Heat Pump Water Heaters under provisional status with a sunset date of December 31st, 2014.”