On a summer day, if you go down into a cave, you'll feel the earth's coolness. Under the ground, the earth maintains a 55- to 58-degree temperature. It stays this temperature all winter, too.
Geothermal heating finds a way to deliver the earth's coolness into your home in summer. In winter, it delivers heat. In the most basic sense, it transfers heat from the ground to your home.
To install a geothermal system, contractors would drill or dig into the ground in your backyard, and lay flexible pipes in a loop. The pipes are filled with a mixture of water and environmentally-friendly antifreeze.
The closed loop of pipes are hooked up to a heat pump inside your utility room. A flow center in the system keeps the liquid constantly moving through the pipes. It keeps recirculating, and we keep taking heat from the ground. The heat is transferred from the ground to the liquid, and the heat pump pulls the heat from the liquid."
Even though the earth's temperature measures only 55 degrees, contractors can easily design a geothermal system with enough capacity to keep a home at a toasty 72 degrees, or warmer, on a zero-degree day in January.
Some homeowners like to buy a system with a lot of capacity to keep it very warm on very cold days. It's more economical, however, to install a system with just enough capacity for the house and use an auxiliary electric heat coil for bitterly cold days.