The geothermal heat pump, also known as the ground source heat pump, is a highly efficient renewable energy technology that is gaining wide spread acceptance for both residential and commercial applications. Geothermal heat pumps are used for heating and cooling, as well as water heating. Its great advantage is that it works by concentrating naturally existing heat, rather than by producing heat through combustion of fossil fuels. Today, more than ever, homeowners and business owners are discovering the benefits of these systems which tap into the relatively constant temperature of the earth.
The technology relies on the fact that the earth (beneath the surface) remains at a relatively constant temperature throughout the year, warmer than the air above it during the winter and cooler in the summer. The geothermal heat pump takes advantage of this by transferring heat stored in the earth or in ground water into a building during winter, and transferring it out of the building and back into the ground during the summer. The ground, in other words, acts as a heat source in the winter and a heat sink in the summer.
To use the earth as a heat source/sink, a series of pipes, commonly called a “loop,” is buried in the ground near the building. The loop can be buried either vertically or horizontally. The loop circulates a fluid (water or a mixture water and anti-freeze) that absorbs heat from, or relinquishes heat to, the surrounding soil, depending on whether the ambient air is cooler or warmer than the soil.
For heating, a geothermal heat pump removes the heat from the fluid in the earth connection, concentrates it, and then transfers it to the building. For cooling, the process is reversed. Conventional ductwork is generally used to distribute heated or cooled air from the geothermal heat pump throughout the building. However in floor radiant heat can also be used effectively with a geothermal heat pump.
An additional benefit occurs by utilizing the waste heat that is removed from the building’s interior during the cooling season to provide virtually free hot water. This can result in a total savings in hot water costs of approximately 30% annually and further lower your building’s total emissions.
Geothermal systems can save a consumer 30-70% on their monthly utility bills. More information on the benefits of heating and cooling with geothermal can be found on the Geothermal Exchange Organization’s website www.geoexchange.org.