September 28, 2010

1. HVAC and DHW System Conversion Cost and Energy Use Assumptions for Direct Use of Natural Gas Analysis September 28, 2010

2. Incremental Cost of Conversion Needs to Reflect Changing Federal Standards US DOE must adopt new efficiency standards for furnaces, central AC and heat pumps by May/June 2011. These standards would take effect in 2013 for gas furnaces and 2015 for Central AC and Heat Pump DOE adopted new standards for gas and electric water heaters effective April 16, 2015

3. New Water Heater Standards • Electric • 55 gallon & smaller tanks =>EF 95 • Above 55 gallon tanks => EF 2.0 • Gas (storage) • 55 gallon & smaller tanks => EF 62 • Above 55 gallon tanks => EF 75 • Gas (tankless) => EF 82

4. Consensus Recommendation on HVAC Equipment Efficiency Standards • DOE has been petitioned to adopt a consensus recommendation on standards for gas furnaces, heat pumps and central AC • Consensus recommendation from AHRI (HVAC manufacturer’s trade association) and ACEEE, NRDC, ASE, NEEP, CEC, ASAP & NPCC

5. Implications for Base Case Efficiency

6. Revised Baseline Conversion Cost Estimates HVAC Systems

7. Revised Baseline Conversion Cost Estimates HVAC Systems (No Existing Air Conditioning) Issue: How should we treat “added CAC service” from heat pump?

8. Revised High Efficiency Conversion Cost Estimates

9. Revised Conversion Cost for Water Heating Systems* *Not including gas service extension or electrical panel size increase

10. Tank Size Distribution Assumptions Approximately 10% of electric water heaters and 4% of gas water heaters are greater than 55 gallons, hence are subject to the EF 2.0 and EF 75 standards.

11. Energy Use Implications of New Standards • Higher efficiency requirements for replacement water heaters, furnaces & heat pumps establish lower “baseline use” for replacement of existing systems • Example: • Prior assumptions - Consumer can replace existing 66 gal. electric water heater with EF-0.88 electric water heater or convert to EF-0.54 gas water heater. Base case electric use = • Revised assumptions - Consumer can replace existing electric water heater with EF-2.0 electric water heater or convert to EF-75 gas water heater.

12. Revised Energy Use Methodology Baseline home prior to conversion originally modeled “as found” (i.e., partially weatherized) Revised approach models conversion options (gas or electric) as “last measure in” (i.e., fully weatherized) consistent with 6th Plan and RTF methodology for other retrofit measures

13. Space Conditioning Estimates • Source: SEEM calibrated simulation results from weatherization and heat pump conversion/upgrade analysis • Gas consumption assumes same input assumptions as electric forced air, adjusted for furnace conversion efficiency (AFUE 90%) • Climate = PNW Weighted Average • Should we do each heating zone analysis after initial results are reviewed?

14. Home Sized Revised to Reflect Correlation with System Types and Basements* *Source: Analysis of Super Good Cents sub-metered data – N= 603 homes

15. Base Case Single Family Energy Use Assumptions – Space Conditioning

16. Base Case Multifamily Energy Use Assumptions – Space Conditioning

17. Base Case Water Heating Assumptions

20. ETO Gas Tankless Water Heater Cost

21. Retrofit Duct System Cost

22. Electric FAF Replacement Cost