The geothermal heat pump is a highly efficient renewable energy that is gaining wide acceptance as a heating and cooling source for use in both residential and commercial buildings. Geothermal heating and cooling uses the relatively constant temperature of the earth usually between 50 and 60 degrees to heat and cool homes and businesses. The geothermal heat pump uses 40-70 % less energy than traditional heating and cooling systems. Geothermal heat pumps are used for space heating and cooling, as well as water heating. 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, very much like a cave. Geothermal energy is clean (emits little or no greenhouse gases), reliable (95%), and homegrown (making us less dependent on foreign oil).
A geothermal heat pump system consists of pipes that are buried in the ground, a heat exchanger, and ductwork into the building. In winter, heat from the warmer ground goes through the heat exchanger and ductwork into the building. In summer, hot air from the house is pulled through the heat exchanger into the cooler ground.
A geothermal heat pump system costs about $2,500 per ton of capacity. The typically sized home would use a three-ton unit costing roughly $7,500. That initial cost is nearly twice the price of a regular heat pump system that would probably cost about $4,000. Drilling costs which range from $10,000 to $30,000 or more also have to be added in. The investment can usually be recouped in five to ten years.
Geothermal heat pumps are durable and require little maintenance. They have fewer mechanical components than other systems, and most of those components are underground, sheltered from the weather. The underground piping used in the system is often guaranteed to last 25 to 50 years and is virtually worry-free. The components inside the house are small and easily accessible for maintenance. Air is distributed through ductwork, just as in a regular forced-air system.