About geothermal

What does the word "geothermal" mean and how does it work? Geothermal can mean heat that comes from within the sun, or a method of heating and cooling with the energy of the earth.

Every day, the earth absorbs over half of the sun's energy. Geothermal systems rely primarily on this stored solar energy to heat or cool a building and provide domestic hot water. Geoexchange systems use a loop field and a ground-source heat pump to concentrate heat from the earth and transfer it into a building in winter, or to transfer heat from a building into the earth in summer.

Geoexchange uses the same heat pump system for heating and cooling. A common example of a heat pump is a refrigerator, which concentrates and extracts heat from the interior, and rejects it into the surrounding space.

By transferring thermal energy rather than creating it through combustion or electrical resistance, geoexchange systems achieve very high efficiencies. For each unit of electrical energy consumed by a heat pump, four to five units of heat energy are moved from the earth to your building.

Ground source heat pumps use a network of fluid-filled pipes to transfer heat to and from the earth. The pipes can be inserted into vertical boreholes, buried in horizontal trenches, slinky pits or submerged in ponds, lakes, or rivers.

How it works

Outdoor temperatures fluctuate with the changing seasons, but underground temperatures don't. Four to six feet below the earth's surface, temperatures remain relatively constant year-round.

A geothermal system, which typically consists of an indoor unit and a buried earth loop, capitalizes on these constant temperatures to provide "free" energy.

In the winter, fluid circulating through the system's earth loop absorbs stored heat and carries it indoors. The indoor unit compresses the heat to a higher temperature and distributes it throughout the your home or building.

In the summer, the system reverses, pulling heat from the building, carrying it through the earth loop and depositing it in the cooler earth.