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.
Ground source heating and cooling provides high-comfort and cost-effectiveness with an environmentally friendly technology that makes use of the Earth's capacity to store energy in the form of heat. Geothermal Heating Systems move heat from the earth or water into a building, or from a building back into the earth. A small amount of electricity is used to operate pumps, fans, controls, and small 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.
Quite a number of new residential systems come with desuperheaters, by which excess heat is transferred to the home's hot water storage tank from the geothermal heat pump's compressor, providing a highly efficient means of heating water. But in the spring and autumn, during which the geothermal heat pump system does not operate, the desuperheater will not provide hot water. However, because of the geothermal system's significant advantage in efficiency compared to other water heating methods, 'full demand' systems using a separate heat exchanger to meet hot water needs cost-effectively are now being offered by some manufacturers.
