Heat Pumps 101

Air source heat pumps (ASHP) are electric devices that provide heating and cooling by moving heat into a building (for heating) or out of a building (for cooling).

Heat pumps do not create heat through burning fossil fuels like conventional heating systems. Instead, heat pumps transfer heat from one place to another by using a refrigerant that absorbs heat from the air and moves it in or out of a building. This is similar to the way that a refrigerator or air conditioner works—except that it can move heat in either direction to provide both heating and cooling.

Since it takes far less energy to move heat than it does to create heat, air source heat pumps are much more efficient. While a fossil fuel heating system is 80-90% efficient (wasting 10-20% of every dollar you spend on oil, gas, or propane), an air source heat pump can be 200-400% efficient, providing 2-4 units of heat for every unit of electricity you pay for. The efficiency can be greater than 100% because some energy comes from heat in the environment around the heat pump.

Air source heat pumps are considered to be clean heating and cooling technologies because they burn no fossil fuels. The electricity that powers a heat pump can come from renewable sources like rooftop solar. Even if a heat pump is powered by electricity from the grid, it will greatly reduce greenhouse gas emissions from fossil fuels while improving indoor air quality. They naturally provide air filtering and dehumidification and can enhance comfort in your home or business.

Air source heat pumps are installed as either supplemental systems (displacing some but not all of the existing heating/cooling system) or as primary systems (completely replacing the existing heating/cooling system). It is also possible to keep the existing heating/cooling system in place as a backup. Special controls are available to coordinate with your existing system