Air Source Heat Pumps
How They Work
In the winter, the air source heat pump draws heat from the outside air and moves it to the indoor air then distributes it through the ducts in your home. The heat pump contains a reversing valve which reverses the flow of refrigerant. In the summer, the reversed process, draws heat from your indoor air and releases it outdoors. At the same time it also dehumidifies the indoor air as it cools it.
More About Heat Pumps
Heat pumps are assigned two efficiency ratings, a SEER rating based on a unit's cooling efficiency and an HSPF rating based on a unit's heating efficiency.
SEER Rating - The SEER (Seasonal Energy Efficiency Ratio) rating is used to identify the cooling efficiency of both traditional air conditioners and heat pumps. The SEER rating indicates how efficiently the unit utilizes electricity: the higher the rating, the less electricity the unit requires to cool a given area.
HSPF Rating - The HSPF (Heating Seasonal Performance Factor) rating is used to identify the heating efficiency of heat pumps: the higher the rating, the less electricity the heat pump uses to heat a given area.
Initial Cost vs. Long Term Expense
Generally speaking, heat pumps with the highest SEER and HSPF ratings are more expensive to purchase than their lower rated counterparts. However, because they utilize less electricity, they can actually save you money in the long run.