Types of Heat Pumps

Most heat pumps have two main parts, the outdoor unit and the indoor unit. The outdoor unit includes a heat exchanger, compressor, and a fan. This is where heat from the outside air is transferred inside during the heating season, and where heat from inside the home is transferred out during the cooling season. The indoor unit contains a heat exchanger and a fan that distributes heated or cooled air through the duct system into the home.

Air Source: An air source heat pump (the most common type) gets heat from the outdoor air and usually consists of an outside unit connected to an indoor unit. Ductwork is connected to the indoor unit to supply the heated or cooled air to the rooms in the home.

Geothermal: Geothermal heat pumps consist of ground source and water source. Ground source heat pumps use heat from the ground rather than from outdoor air. An advantage to this type is that the ground is a constant temperature without the common fluctuations in air temperatures. A ground source heat pump is less expensive to operate than an air source. These systems have a higher initial cost than air source and the installation requires some excavation to install pipes in the ground.

Water Source: Water source heat pumps use a body of water; either well water, a pond, or a stream for their source of heat. They absorb heat from the water, which is usually warmer and more stable than winter air. Efficiency is higher with this system compared to the air-source heat pump, but initial investment is also higher.