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.
