1. RTF: Deemed Measure Analysis: Ground Source Heat Pumps Final Summary and Recommendation April 5th, 2011

2. GSHP Deemed Measure Analysis Project Objectives Assumptions and Basecase GSHP Energy Modeling Methodolgy GSHP Sizing GSHP Costs SEEM Runs and Calibration ProCost Runs and Analysis Recommendations

3. RTF GSHP Deemed Measure Study Objectives

4. Subcommittee Members David Baylon, Shawn Oram, Ben Larson, Poppy Storm- Ecotope Tom Eckman – NW Council Gillian Charles - NW Council Adam Hadley – Hadley Energy Warren Cook - PECI Danielle Gidding – BPA Gary Grayson – Idaho Power Todd Greenwell - Idaho Power Jim Haberman - BPA David Hales – WSU Energy Office Mark Jerome – KAM Energy/Pacific Air Comfort Mark Johnson – BPA Bruce Manclark – Delta T David Maul - Maul Energy Advisors Jim Maunder - Ravalli Electric Andres Morrison – Ecos Consulting Guy Nelson - UGWG Nick O’Neil - Energy Trust Brady Peeks - NW Energy Works Dennis Rominger – PSE

5. Summary of Activities Conference calls and Goto Meetings were setup with the Sub-Committee on the following dates. 1. GSHP Sub-Committee Kickoff Meeting: Jan. 6 th, 2011 2. GSHP Measure Review and Research: Jan 25 th 2011 3. GSHP SEEM Integration and Costs : Feb. 23 rd, 2011 4. GSHP Draft Recommendations : Mar. 16 th, 2011 5. GSHP RTF Presentations : April 5 th, 2011

6. Review of Scope: Update Ground Source Heat Pump (GSHP) measure definitions, energy savings, costs, cost-effectiveness, and status for GSHP measures for Single Family and Manufactured Homes.

7. GSHP Deemed Savings Sub-Measures  GSHP upgrade from an ASHP  PTCS Duct Sealing  PTCS Cx, controls and sizing  De-superheat for DHW Note: GSHP is last measure in. PTCS duct sealing, Cx, controls and sizing are already present in the ASHP base.

8. Assumptions and Base-case

9. Typical GSHP System

10. Prototype Modeling Four Prototype homes  Manufactured home 1568sf  Single Family 2200sf  Single Family w/Bsmt 2688sf  Large Single Family 5000sf (Non-Standard Prototype) 3 Heating Zones, 3 Cooling Zones Heating, Cooling, and DHW impacts C/B Analysis (ProCost)

11. Systems Assumption Basecase Systems Airside Source Heat Pump (HSPF 8.5, SEER 14) Electric DHW (0.90 EF) Retrofit, Fully Weatherized New Construction PTCS Duct Sealing, Cx, Controls and Sizing Proposed Systems Water-to-Air Heat Pump ((COP 3.7 32F EWT, 18.2 EER 77F EWT ) w/ ECM Motor, CV, single stage compressor) GSHP sized to meet load at 25 deg F OSA Electric Resistance installed w/ and w/o DHW Desuperheater buffer tank Horizontal Closed Loop Focus (lowest cost loops)

12. GSHP Energy Modeling Approach

13. Outline of Modeling Develop GSHP W:A Heat Pump into SEEM. Develop annual ground loop curve into SEEM Develop De-Superheater Savings into SEEM Calibration with actual ground source heat pump energy monitoring study performed in1996 on mulitple sites in MT.(Missoula GSHP Study: co-op Maunder 1996 )

14. Heat Pumps: Heating Capacity

15. Heat Pumps: Heating Performance

16. Ground Loop Curves Used Tewtr = 27*sin(2pi / 8760 * hoy + 3.5) + 55.5 Tewtr = 22*sin(2pi / 8760 * hoy + 3.5) + 55.5 Tewtr = 17*sin(2pi / 8760 * hoy + 3.5) + 55.5

17. GSHP Sizing & Costs

18. System Sizing Assumptions Base-Case: ASHP sized to meet load at 30 deg OSA temp. Proposed: GSHP sized to meet load at 25 deg OSA and 30 degree EWT. Ground Loop is sized using IGSHPA’s CLGS program. Inputs: 1. Full Load Hours: (Total BTU’s)/(Heat Pump Capacity) (Used SEEM for BTU’s) 2. Desired Loop Design Temp = 30F EWT 3. Ground Characteristics and Location 4. Loop Type (Used 4 Pipe Trenches) Outputs: Total Loop Length Calculated

19. GSHP Total Pipe Length Results (NC) Total foot of pipe in ground depth5' 8' HOUSEHZ1HZ2HZ3 1568964254445722936 22001345322657913729 26881313316457163645 50001914455281755293 Total Design Heat Load (Btu/hr) HZ1HZ2HZ3 1568 18,350 24,559 28,471 2200 23,562 31,881 37,070 2688 21,506 28,555 32,998 5000 39,292 48,275 55,778

20. GSHP Loop Size/Ton of House Load Foot of pipe per ton of house load, NOT equipment load depth5' 8' HOUSEHZ1HZ2HZ3 1568630124319271237 2200685121418751207 2688733133020791326 5000633113217591139 Example: 1568 house in HZ2 is 24,559 btu/hr peak load. Sizing selection is 2 ton of GSHP w/elec resistance and (4x) 600’ ground loops.

21. GSHP Installed Costs (inside only) Heat Pump Size All Inside Heat Pump, pumps, piping w/ no ducts Price Per Ton 2$6,633$3,316 3$7,319$2,440 4$8,576$2,144 5$9,556$1,911 6$10,100$1,683

22. GSHP Loop Costs $1300 per 600’ loop and trench, all pricing scaled from this.

23. GSHP/ASHP System Costs (NC) GSHP 1ASHPGSHP 2ASHPGSHP 3ASHP S.F.HZ1 HZ2 HZ3 1568$8,721$5,273$12,145$5,273$16,175$5,273 2200$9,890$5,573$13,965$5,273$19,095$5,573 2688$9,821$5,573$13,831$5,573$18,822$5,573 5000$12,094$6,173$17,810$6,173$25,150$6,173

24. GSHP Incremental Costs (NC)

25. Desuperheat $500 adder without preheat tank $1000 adder with preheat tank Range of DHW savings 800-2200 kwh (only runs when heat pump runs).

26. Calibration

27. Missoula Study Calibration Source

28. SEEM GSHP Module Calibration Metered data on 19 houses with GSHPs: Missoula Electric Cooperative GSHP Demonstration Project, 1996 Created SEEM runs based on reported insulation values & floor areas. Two SEEM prototypes used (1344 over sealed crawl and 2688 basement) to match average floor area Strategy: Match reported equipment output to SEEM equipment output No heat pumps involved in this step – it validates the inputs only Use validated inputs with GSHP model Matched GSHP design: 45F loop (vertical bores in aquifer) Very little auxiliary heat reported so used 35F outside T lockout to limit aux heat use in simulations Next step is to derate COP of SEEM GSHP to match those in 1996 study (3.7  2.5) Final piece is determining useable desuperheat energy (simply used a multiplier to derate SEEM output to match metered data accounting for COP differences)

29. Calibration Results MT Study N= 19 SEEM Floor Area (ft^2)19851949 Heat Pump Size (tons)2.632.73 Equipment Heat Output (kWh)1240412644 GSHP+Aux (kWh)52115479 Aux Heat (kWh)222301 Space Heating Savings (kWh)71937165 Useable Desuperheat (kWh)967962 Match is good. No tweaks to set point or internal gains were made. Duct sealing was reported so was used. No special infiltration measures used (0.35ACHn). Weather file used was Missoula TMY3 but reported energy data was not weather normalized.  potential source of error. But, graph in report shows mean daily temperature reported was slightly higher than a “normal” year. “Normal” not defined.

30. SEEM Runs & Pro-Cost Runs

31. Weatherized SEEM/ProCost Results Existing Housing B/C Ratios, no desupheatExisting Housing B/C Ratios, w/ desupheat Climate1568220026885000Climate1568220026885000 HZ1CZ10.510.570.480.56HZ1CZ10.750.710.650.68 HZ1CZ20.540.600.490.58HZ1CZ20.770.730.670.70 HZ1CZ30.590.650.540.62HZ1CZ30.810.770.700.73 HZ2CZ10.550.620.500.61HZ2CZ10.720.710.640.68 HZ2CZ20.560.630.510.62HZ2CZ20.730.720.640.69 HZ2CZ30.590.660.530.64HZ2CZ30.75 0.660.71 HZ3CZ10.540.590.490.58HZ3CZ10.65 0.580.63 HZ3CZ20.550.600.490.59HZ3CZ20.66 0.590.64 HZ3CZ30.560.610.500.60HZ3CZ30.680.670.600.65 Existing Housing kWh Savings, no desupheatExisting Housing kWh Savings, w/ desupheat Climate1568220026885000Climate1568220026885000 HZ1CZ11088176011622343HZ1CZ12212276721493402 HZ1CZ21147184112102425HZ1CZ22271284821973484 HZ1CZ31261199513162602HZ1CZ32385300223033661 HZ2CZ12336381524864956HZ2CZ13692500837076192 HZ2CZ22395389625345039HZ2CZ23751508837556275 HZ2CZ32508405026405215HZ2CZ33865524338626451 HZ3CZ13624590639137676HZ3CZ15041713152538970 HZ3CZ23683598739617758HZ3CZ25100721153019053 HZ3CZ33797614140677935HZ3CZ35213736654079229

32. New Construction SEEM/ProCost Results New Housing B/C Ratios, no desupheatNew Housing B/C Ratios, w/ desupheat Climate1568220026885000Climate1568220026885000 HZ1CZ10.450.550.370.57HZ1CZ10.670.700.530.69 HZ1CZ20.480.580.390.59HZ1CZ20.690.720.540.71 HZ1CZ30.530.630.420.63HZ1CZ30.730.760.570.74 HZ2CZ10.480.600.400.60HZ2CZ10.640.700.520.68 HZ2CZ20.490.610.410.61HZ2CZ20.660.710.530.69 HZ2CZ30.520.640.430.63HZ2CZ30.680.740.550.71 HZ3CZ10.470.580.390.57HZ3CZ10.590.640.490.62 HZ3CZ20.480.580.400.58HZ3CZ20.600.650.490.63 HZ3CZ30.500.600.410.59HZ3CZ30.610.660.500.64 New Housing kWh Savings, no desupheatNew Housing kWh Savings, w/ desupheat Climate1568220026885000Climate1568220026885000 HZ1CZ195214509572046HZ1CZ11966241418093061 HZ1CZ21010152410032123HZ1CZ22024248918553138 HZ1CZ31121166511042285HZ1CZ32135262919563300 HZ2CZ12025308520344270HZ2CZ13284421931205450 HZ2CZ22083316020804347HZ2CZ23342429331665526 HZ2CZ32194330021814509HZ2CZ33453443332675688 HZ3CZ13133473831756584HZ3CZ14472588543997810 HZ3CZ23192481332216660HZ3CZ24530595944457886 HZ3CZ33302495333226822HZ3CZ34641610045468049

33. Outline Spec & Recommendations

34. Outline Specs GSHP AHRI Rating Point (COP-3.7 at 32F EWT, EER- 18.2 at 77 deg F EWT) Ducted Ground Source Heat Pumps shall be sized to meet load at 25 F OSA temp and assume 30 F incoming loop temps. Ducted GSHP shall include resistance heat with lockout over 35 F OSA temps. Ground Loops shall be designed for 30 deg entering water temps at peak using an IGSHPA recognized sizing program. Loop pumps shall be sized no larger than 150 watts/nominal ton of heat pump. Desuperheater require a preheat buffer tank with no heat installed in preheat tank.

35. Recommendations Revise all existing measures with results from this analysis. Adopt Savings Numbers for GSHP List GSHP as NON-cost-effective deemed measure. Ground Source Heat Pumps are NOT cost effective over ASHP’s. B/C ratios with an electric furnace as the basecase should be explored as future scope.

36. Discussion & Decisions