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Geothermal Heat Pumps: Superior New Technology

by Ryan McCall

A device that extracts heat from beneath the Earth is called a Geothermal Heat Pump (GHP). The GHP functions based on the principle that heat will move from higher to lower temperature materials, by either conduction or convention (air currents). These pumps absorb energy from both the ground and bodies of water and uses it to provide space and water heating. This is able to occur because the Earth absorbs 50% of the suns heat that reaches the Earth's service.

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.

Even though the cost of installation of a geothermal system can be several times that of traditional heating and cooling system, the additional costs are returned in energy savings in 5 to 10 years. The life of such a system is estimated at 25 years for the interior components and 50 or more years for the ground loop piping. Approximately 50,000 geothermal heating systems are installed in the US each year. Geothermal heat pumps are practical in most areas. They can use the Earth as a heat source in the winter and a heat sink 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.

Published October 2nd, 2008

Filed in Environment