1. New MT Houses with Ground Source Heat Pumps Energy Savings and Costs June 2 nd, 2009 Regional Technical Forum 1

2. Background On March 2 nd, 2009, the RTF approved energy savings and costs for MT Houses with – Zonal Electric, Electric FAF w/ and w/o CAC, and Air Source Heat Pump heating systems Savings for cases without PTCS duct sealing range from 3,400 to 7,200 kWh/year (HZs 2 & 3) Savings for cases with PTCS duct sealing range from 4,800 to 9,500 kWh/year (HZs 2 & 3) Savings assume like pre- and post-heating system types Recently, the RTF was requested by Montana utilities to 1.Analyze energy savings and costs for MT Houses with GSHPs, including conversions from electric forced air furnaces to GSHPs, and 2.Look at the cost-effectiveness for GSHPs in large homes. 2

3. Background: MT House Specifications 3

4. Background: MT House Specifications (continued) Reminder: Specs were approved at the January 6, 2009 RTF meeting 4

5. New MT House Input Assumptions Energy Savings – SEEM FAF w/CAC Use adjusted for GSHP COP and SEER GSHP Heating COP = 3.3 (heating season average) GSHP SEER = 16 (versus 13 SEER modeled in SEEM) Cost: – Where baseline is Zonal or FAF: $25 annual O&M (outdoor unit maintenance) $2,000 every 20 years (component replacement) All other savings, cost, and measure life assumptions remain the same as the March 2 nd analysis. 5

6. Capital Cost – Heating Zone 2 6

7. Capital Cost – Heating Zone 3 7

8. Results – Energy Savings – HZ 2 8

9. Results – Energy Savings – HZ 3 9

10. Results – B/C – HZ 2 10

11. Results – B/C – HZ 3 11

12. Results – Levelized Cost – HZ2 12

13. Results – Levelized Cost – HZ3 13

14. Inputs for Large Homes Quick development of a new large home prototype: – Added a second story to the 2688 ft 2 basement prototype – Results: 4032 ft 2 Doubled window area, wall area, and door area No change to attic, slab, or basement wall areas Quick SEEM Runs – Kalispell weather only – Did not re-run cooling (used results from 2688 basement) – Did not re-run air-source heat pump cases Cost: – Where baseline is Zonal or FAF : $40 annual O&M (outdoor unit maintenance) $3,000 every 20 years (component replacement) – Shell measure costs increased due to increased window, wall, and door areas 14

15. Capital Cost – Heating Zone 3 15

16. Results – Energy Savings – HZ 3 16

17. Results – B/C – HZ 3 17

18. Results – Levelized Cost – HZ3 18

19. Decisions Approve Savings and Costs for MT House with GSHP GSHP? Approve Savings and Costs for MT House with non-GSHP baseline heating systems? (ASHP GSHP; FAF GSHP; and/or Zonal GSHP) – Issues 1.This would be the RTFs first heating system conversion measure for new construction. 2.In a new construction situation, how does a program know what someone would have put in? – Options 1.Disallow heating system conversions for new construction measures 2.Approve the savings and costs that assume non-GSHP heating systems as the baseline A.Allow programs to decide what to use as the baseline heating system type on a case-by-case basis, or B.RTF to choose a baseline heating system, or C.RTF to develop a weighted average savings based on an assumed mix of baseline heating equipment Large home analysis – Issues 1.Would programs be willing/able to screen out participants based on house size? 2.If only large houses are allowed, could be interpreted that the Region supports increased house sizes. – Options 1.Pursue making a distinction for large house sizes in the savings and cost-effectiveness analysis A.Refine the large home prototype and associated analysis for GSHPs a)Put in place a large home measure category b)Incorporate the large home results by developing an average weighting for the large home prototype B.Develop a deemed calculator with specific house information as inputs (based on SEEM). 2.Continue using the existing method, which incorporates a weighted average house size based on the current prototypes 19