Geothermal Heat Pumps: Cost Effective And Environmentally Sound
A Geothermal Heat Pump (GHP) is an apparatus that extracts heat from below the surface of earth. It works on the principle that heat flows from higher temperature substances to lower temperature substances via conduction or via convection (air currents). Geothermal Heat Pumps take in heat from the earth or water bodies to provide space and water heating. This works since the earth traps nearly half the sun’s energy that is received by the earth.
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.
GHPs utilize the relatively constant temperature of the ground or water several feet below the surface as a source of heating and cooling and are appropriate for both retrofit or new homes. In addition to space heating and cooling, geothermal heat pumps can provide hot water with virtually no additional energy requirements because GHPs don’t create heat; they merely move it from one area to another. This is a relatively new technology that can save homeowners money
Although the initial cost of a new geothermal system is generally more expensive than a traditional heating and cooling system, the extra investment is returned within five to ten years. The ground loop piping is estimated to last over fifty years, and even the internal parts have about a 25 year life span. Every year about 50,000 new geothermal heating systems are added in the United States. They’re very reasonable for most areas and can use the Earth for heating when temperatures drop and as a heat sink when it’s hot outside.
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.
