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Geothermal Heat Pumps

If you're planning to build a new house, office building, or school, or replace your heating and cooling system, you may want to consider a geothermal heat pump (GHP) system. GHP systems are also known as ground-source, or water-source heat pumps (as opposed to air-source heat pumps). Regardless of what you call them, energy-efficient geothermal heat pumps are available today for both residential and commercial building applications.

A GHP system can be installed in virtually any area of the country and will save energy and money.

The biggest benefit of GHPs is that they use 25%–50% less electricity than conventional heating or cooling systems. This translates into a GHP using one unit of electricity to move three units of heat from the earth. According to EPA, geothermal heat pumps can reduce energy consumption—and corresponding emissions—up to 44% compared to air-source heat pumps and up to 72% compared to electric resistance heating with standard air-conditioning equipment. GHPs also improve humidity control by maintaining about 50% relative indoor humidity, making GHPs very effective in humid areas.

Geothermal heat pump systems allow for design flexibility and can be installed in both new and retrofit situations. Because the hardware requires less space than that needed by conventional HVAC systems, the equipment rooms can be greatly scaled down in size, freeing space for productive use. GHP systems also provide excellent "zone" space conditioning, allowing different parts of your home to be heated or cooled to different temperatures.

Because GHP systems have relatively few moving parts, and because those parts are sheltered inside a building, they are durable and highly reliable. The underground piping often carries warranties of 25–50 years, and the heat pumps often last 20 years or more. Since they usually have no outdoor compressors, GHPs are not susceptible to vandalism. On the other hand, the components in the living space are easily accessible, which increases the convenience factor and helps ensure that the upkeep is done on a timely basis.

Because they have no outside condensing units like air conditioners, there's no concern about noise outside the home. A two-speed GHP system is so quiet inside a house that users do not know it is operating: there are no tell-tale blasts of cold or hot air.

Articles and Publications

Geothermal Heat Pumps

A brief primer from the U.S. Department of Energy that explains geothermal heat pump technology and offers links to related publications.

Geothermal or Ground-source Heat Pumps

An educational overview of geothermal heat pumps from the Consumer Energy Center. Addresses cost, durability, types, and more.

An Information Survival Kit for the Prospective Geothermal Heat Pump Owner

Produced by Kevin Rafferty and the Geo-Heat Center, this "survival kit" provides information to help determine whether GHP technology is suitable for your home. It also provides answers to some common questions about this technology.


DOE Geothermal Technologies Program

EERE's Geothermal Technologies Program works in partnership with U.S. industry to establish geothermal energy as an economically competitive contributor to the U.S. energy supply. The program website includes a host of useful information on geothermal technologies.

ENERGY STAR-Labeled Geothermal Heat Pumps

Information on geothermal heat pumps that have received the ENERGY STAR certification for energy-efficient performance. Includes a list of qualifying products and a list of manufacturers that produce qualifying products.

Geo-Heat Center

Part of the Oregon Institute of Technology, the Center provides technological information to a variety of audiences in an effort to expand the use of geothermal energy.

Geothermal Heat Pump Consortium

Provides extensive information regarding geothermal heat pumps, including consumer brochures, technical reports, and a database of installers. The Web page contains case studies, published articles, list of equipment suppliers, and workshop schedules and locations. The GHPC has broad-based support and participation from DOE, the utility sector, and geothermal associations and manufacturers.

International Ground Source Heat Pump Association

Established in 1987 to advance geothermal/ground source heat pump technology on a local, state, national, and international level. Provides a list of equipment manufacturers, a state-by-state list of installers, and numerous design manuals and brochures for contractors, homeowners, students, and the general public.


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