A geothermal heating and cooling system consists of three main pieces of equipment:

​

1. Underground loops of piping act as a heat exchanger.

     When the liquid antifreeze solution passes through the loops, it absorbs heat from the ground, causing it to evaporate.

2. An indoor heat pump unit includes the condenser coils.
      When the heated antifreeze vapor passes through the coils, it gives up its heat to the surrounding air and condenses       back into a liquid.

3.  An air-handling system takes the heated air and moves it through ductwork to individual rooms.

 

During the summer, a reversing valve switches the indoor coil to act as the evaporator and the underground pipes to act as the condenser. All components of a geothermal system - except the underground loops - are placed inside a building, usually in the basement, garage or crawl space. Since they're indoors, the compressor and other vital parts are protected, with most having a life span of 20 years or more. The geothermal equipment qualifies for a 30% tax credit with no cap.

 

Not all geo systems are alike - most provide summer air conditioning, but some models are designed only for winter heating.

 

Geothermal heat pumps also can be different in the way they're designed. Self-contained units combine the blower, compressor, heat exchanger and coil in a single cabinet.