What Is A Geothermal System And How Does It Work?

Every day, the earth absorbs over half of the sun’s energy. Geothermal (also known as geoexchange or earth energy) 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, where it is stored for extraction later. Geoexchange uses the same heat pump system for both 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, three to four units of heat energy are moved from the earth to your building.

The two basic types of geoexchange systems are open loop and closed loop. Closed loop systems are preferred for their reliability and low maintenance.

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, or submerged in the ocean, lakes, or rivers.