How Well are Heat Pumps Really Installed
Heat pumps are an important technology for reducing the energy usedto heat homes. Bonneville Power Administration and many of the retail electric utilities in the Pacific Northwest have worked for many years to improve the practices of firms that install heat pumps, so that they can achieve their full potential to save energy. SBW conducted this field study to gather data on current installation practices related to appropriate sizing, commissioning, and thermostat controls–all of which affect how efficiently heat pumps operate.
The results of the study indicate that the region still has a long way to go to achieve the most efficient commissioning and sizing practices. Not much has improved in the current installation practices since 2005, when the last study was performed, except that heat pumps tend to be oversized rather than undersized in the eastern part of the region, and more homes appear to have low refrigerant charge now than in 2005. The only significant improvements we found were with various control schemes (auxiliary heat lock out and compressor cutoff).