A Geothermal Heat Pump (GHP)is a device that extracts heat from beneath the ground. It functions based on the fact that heat will flow from higher temperature materials to lower temperature materials by conduction or by convection (air currents). Geothermal pumps absorb energy from the ground or bodies of water to provide space and water heating. This works because the earth absorbs about 50% of the sun's energy that reaches the surface of the planet.

Taking advantage of the earth's ability to store thermal energy, ground source heating and cooling is inexpensive and environmentally friendly while still providing lots of heat. These pump systems can either pump heat from the ground into a building, or in warmer weather, from the building back into the ground. It doesn't take much electricity to run the pumps and fans, along with a compressor.

Geothermal heat pumps (GHPs) are among the most efficient and comfortable heating and cooling technologies currently available for homes and other buildings. These ground-source heat pumps use the natural heat storage capacity of the earth or ground water to provide energy efficient heating and cooling. Most GHPs are installed with "Desuperheaters" which collect waste heat from the compressor and use it to pre-heat domestic hot water for free. This is a new money-saving technology for homes.

It can cost several times to install a geothermal heating and cooling system, compared to the traditional kind. However, those costs are recovered over the next five to ten years, in the form of saving on energy costs. The interior components of these systems can easily last twenty-five years, and the piping in the ground can last fifty years. These systems are practical in most areas, and about 50,000 new systems are put in every year. They heat in the winter, and cool in the summer.

Many new residential systems are equipped with desuperheaters which transfer excess heat from the geothermal heat pump's compressor to the home's hot water storage tank providing very efficient water heating. However, the desuperheater will not provide hot water during the spring and fall when the geothermal heat pump system is not operating. But because the geothermal heating system is so much more efficient than other means of water heating, some manufacturers are offering 'full demand' systems that utilize a separate heat exchanger to cost-effectively provide for hot water needs.

Even though the cost of installation of a Geothermal Heating Systems can be several times that of traditional heating and cooling system, the additional costs are returned in energy savings in 5 to 10 years. This is due to the very high efficiency of Geothermal Heat Pumps.