A 14 SEER heat pump is a heat pump that removes 14 British thermal units (BTUs) of heat from indoor air for each kilowatt-hour of energy used to cool the air. This ratio, the seasonal energy efficiency rating, measures only the cooling efficiency of the heat pump.
Because heat pumps work for both heating and cooling, they are given separate ratings for their performance in these areas. The heating system performance factor is the ratio of total space heating required, measured in BTUs, to the energy consumed to generate the heat as measured in kilowatt-hours. To earn the Department of Energy's Energy Star certification, a heat pump must have a SEER of at least 12 and an HSPF of at least 7. A high SEER rating is most important for systems to be used in warm climates, while the HSPF is more important in cold climates.
When selecting a heat pump, size can be as important a consideration as these ratings. A system too small for the home cannot heat or cool it effectively, while one that is too large can make the house drafty in winter and will not dehumidify the air adequately in summer. The construction and sealing of the ductwork that will distribute heated and cooled air are also critical for efficient operation.