How geothermal works

This new technology relies primarily on the Earth’s natural thermal energy, a renewable resource, to heat or cool a house, multi-family dwelling or commercial facility. A few feet beneath the surface, the earth's temperature remains fairly constant. Geothermal takes advantage of this constant temperature to provide extremely efficient heating and cooling. In winter, a water solution circulating through pipes buried in the ground absorbs heat from the earth and carries it into the home or building.

The geothermal system inside the home or building uses a heat pump to concentrate the Earth's thermal energy and then to transfer it to air circulated through standard ductwork to fill the interior space with warmth. In the summer, the process is reversed: heat is extracted from the air in the house and transferred through the heat pump to the ground loop piping. The water solution in the ground loop then carries the excess heat back to the earth. The only external energy needed is the small amount of electricity needed to operate the ground loop pump and fan.

In addition to space conditioning, geothermal heat pumps can be used to provide domestic hot water for all uses including hot tubs and pools.

For additional information, visit the Iowa Geothermal Association website.