Air Source Heat Pumps

Air source heat pumps are basically reversible air conditioners. They move heat from the air in one location to the air in another. They are referred to as "air-to-air" because they take heat from air and move it to other air. This is as opposed to, for example, geothermal heat pumps or water-source heat pumps where the heat source or sink is something other than air like the earth or a pond.

In summer, they operate as air conditioners, removing heat from the home. In winter, they reverse their operation, gathering heat from air outside the home and moving it inside. Most heat pumps deliver conditioned air to the home using ductwork; although packaged, "through-the-wall" systems with no ductwork are available.

Since heat pumps move rather than generate heat, they can be extremely-efficient, delivering more than three times as much heat as they consume in energy. In some parts of the country (especially in mild climates) they are the least expensive way to heat and cool a home.

Heat pumps have the additional advantages of providing heating and cooling in one unit using a single energy source. In addition, heat pumps do not require flues nor their associated roof penetrations.

Geothermal Heat Pumps

Geothermal heat pumps operate like air-to-air heat pumps, moving rather than creating heat; however, they use the ground or water as a heat source and heat sink, rather than outside air. And, because the ground or water temperatures are much more constant year-round (warmer in winter and cooler in summer) geothermal heat pumps operate more efficiently than air-to-air heat pumps.

Geothermal heat pumps are becoming increasingly popular due to their heating and cooling energy efficiency, and related environmental and ownership benefits, especially where ground water is available or soil conditions are favorable.

In the heating mode, a geothermal heat pump typically extracts two-thirds (or more) of the needed energy from the earth or water loop and moves it indoors. Only one-third of the energy needed is purchased power, primarily used to run the compressor. In the summer, geothermal heat pumps move heat from indoors into the relatively cool earth or eater loop. Air-to-air heat pumps, natural gas-, or oil-heating systems.

Additional ownership benefits include more useable space in the home, since the indoor unit can be installed in a portion of an equipment room or small closet. And, there is no visible outdoor unit to suffer deterioration from weather, vandalism, or compressor noise!

Geothermal heat pumps have lower operating, maintenance, and life-cycle costs, increased reliability, and provide greater comfort than other heating and cooling systems. In the years ahead, as fuel costs rise and environmental factors play more important roles in decision-making, we can expect increasing acceptance of this remarkable technology.