Why are Geothermal Heat Pumps Efficient

Geothermal heat pumps are used for space heating and cooling, and if so equipped, also to heat water. Their high efficiencies are gaining more and more popularity for both residential and commercial buildings. It's not hard to see why. Rather than obtain heat through the combustion of fossil fuels, geothermal heat pumps use the natural existing heat from the earth's ground source (http://www1.eere.energy.gov/geothermal/heat pumps.html).

Think of the temperature of the ground as that of a cave. Beneath the earth's surface, the temperature remains relatively constant. Simply put, a geothermal heat pump takes the heat stored in the earth and transfers it into your home or office. During the summer, it does the opposite by transferring the heat from your home or office back into the ground. In other words, the ground acts as a natural heat source in the winter and a heat sink during the summer months.

But how does this highly energy efficient geothermal heat pump do this? First, a series of pipes, called a 'loop,' are buried either vertically or horizontally deep in the group. A water or anti-freeze solution circulates through the surrounding soil absorbing the earth's heat, or in the summer, relinquishing heat. During the winter, heat is removed from the fluid in the earth's connection, concentrated, and transferred into your home. The processed is reversed in the summer; heat is removed from your home, concentrated, and placed back into the ground. Voila! An energy efficient system that reduces greenhouse gas emissions, cuts your electric bill nearly in half, requires lower maintenance, and may even lower your hot water bill.