Geothermal Heaters and Pumps
October 18, 2011 | Geothermal Heaters and Pumps
A geothermal heater, or ground source heat pump, is a device that uses energy stored in the ground to heat and cool buildings. It transfers heat from the Earth into a building and vice versa, depending on the comparative temperatures of the two.
Geothermal energy is heat stored in the Earth. Traditionally, “geothermal” energy meant the heat trapped deep in the Earth’s core and mantle, left there from the planet’s formation and radioactive decay; this type of heat is most plentiful at tectonic plate boundaries. More recently it has also come to include energy stored near the surface of the soil, where it can be easily reached in most parts of the world.
Geothermal heaters can be especially attractive to homeowners who want to support a healthy environment, since they don’t directly use fossil fuels or nuclear power – though they do require some electricity. There are currently about 1 million units installed around the world.
It’s a simple process. Below about 20 feet, the temperature of the ground reflects the average annual temperature of the air above. When this ground or “geothermal” temperature is greater than the ambient temperature of the building, a heat pump will transfer heat from the ground to the building through a heat exchanger. When the geothermal temperature is less than the building temperature, the heat pump will transfer heat from the building into the ground. All this creates a stable ambient temperature in the building. Geothermal heaters also allow for thermal storage, which makes it possible to bank summer heat for the winter months.
Geothermal heaters and pumps come in a wide variety of types and variations. They can be used to provide central heating and cooling for buildings, to provide space heating and cooling, and to provide water heating. They are among the most efficient heating and cooling systems available.
