Geothermal heat pumps have been in use since the late 1940s. As the
technology gets better and the prices continue to fall, they have
recently become more popular for home use. Today, about 80,000
geothermal heat pumps are installed per year in the United States. These
heat pumps are a cost- and energy-efficient way to stay warm during the
long, cold months of winter. Here's how geothermal heat pumps work --
and how you can get one for your home.
Geothermal Heat Pump: Photo by Erin Stancik, shilsholepointe.com
Air temperature can vary dramatically with seasonal changes, as we are all reminded when the weather turns arctic each winter, but a few feet below the earth's surface, it's a different story. Below ground, the earth stays at a relatively constant temperature. Geothermal heat pumps take advantage of this fact of nature. They work by circulating a fluid that absorbs heat from the earth and transfers it into the building to be heated. This method is highly sustainable and more efficient than a traditional air-source heat pump.
How do geothermal heat pumps work? There are four different types of geothermal heat systems, all of which circulate fluid underground to absorb heat. Here are the four types: (1) horizontal systems, which move the fluid through pipes laid underground; (2) vertical systems, which make use of holes bored down into the ground; (3) pond loop systems, in which pipes are submerged in a body of water; and (4) open loop systems, which make use of groundwater. The video below explains more about each of these geothermal heating systems.
At around $8,000, the cost of a residential geothermal heating system may initially seem prohibitive, but the system can pay for itself in just a few years. According to the EPA, a geothermal system can reduce a homeowner's heating and cooling bill by 25 - 50%, compared to a conventional HVAC system. Many states also provide tax incentives for using sustainable energy such as geothermal heat. For more information, check out the US Department of Energy's Database of State Incentives for Renewables and Efficiency.
This winter, consider keeping warm with a geothermal heat pump.
Sources: Energy.gov, Living Green Magazine