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Air Source Heat Pumps

Air Source Heat Pumps. Potential Changes in the RTF’s Specifications & Savings Estimates and Their Impact on C&R Discount Program Credits. Why “Things” Are Changing – New Energy Star Specifications.

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Air Source Heat Pumps

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  1. Air Source Heat Pumps Potential Changes in the RTF’s Specifications & Savings Estimates and Their Impact on C&R Discount Program Credits

  2. Why “Things” Are Changing – New Energy Star Specifications • Energy Star labeled air source heat pumps established new performance criteria effective October 1, 2002 • Split System Minimums • SEER – 13.0 • HSPF - 8.0 • EER – 11.0 • Package System Minimums • SEER – 12.0 • HSPF – 7.6 • EER – 10.5

  3. Why “Things” Are Changing – PNW Climates Are Different • ARI performance ratings (SEER & HSPF) are based on climates that do not match the Northwest’s. • The “West Side” climates are warmer than the rating location – HSPF is higher than label • The “East Side” climates are colder than the rating location – HSPF is lower than label • All of the NW has lower humidity than the rating location – SEER is lower than label

  4. The Impact of Climate on HSPF

  5. Climate Adjusted HSPF

  6. Why Things Are Changing – Control Practices Reduce Performance • Set-Back Thermostats (with or without “ramp up” features) often result in use of electric resistance heat • Timed-defrost controls (particularly on the “East Side”) operate even when relative humidity is too low to produce icing • Compressor “cut-out” temperatures are set too high, so compressor doesn’t operate even when it has a COP above 1.0.

  7. The Impact of Controls on HSPF

  8. Control Adjusted HSPF

  9. Why Things Are Changing - Failure to Properly Commission Heat Pumps • Field studies of heat pump and air conditioner installations reveal • Over/Under Charging of Refrigerant • Low air flow across evaporator coils

  10. Impact of Improper Commissioning on HSPF

  11. Commissioning Adjusted HSPF

  12. Cumulative Impact on HSPF

  13. Cumulative Adjusted HSPF

  14. SEER Doesn’t Match Label Either • High performance air conditioning equipment is designed to “de-humidify” by recovering latent energy (heat of condensation) • Preliminary research appears to show that SEER ratings, when adjusted for the PNW “dry-summer” climate are about 65% of nameplate • Nominal 10 SEER => Real 6.5 SEER

  15. Implications for C&R Discount Values • Difference Between “PTCS” Heat Pump (or CAC) Installations & Non-“PTCS” Installations Increases • Difference between Non-PTCS Heat Pump (or CAC) Installations and “Baseline” Installations Decreases

  16. Example 1 – Pre80 Single Family w/Furnace in Heating & Cooling Zone 1

  17. Example 2 – Post79/Pre93 Single Family w/Furnace in Heating Zone 1 & Cooling Zone 2

  18. Example 3 – Post92 Single Family w/Zonal Heat & No CAC in Heating Zone 1 & Cooling Zone 3

  19. Example 4 – Pre80 Single Family w/Furnace & w/o CAC in Heating & Cooling Zone 2

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