Working

A geothermal system consists of three basic parts. The first part is simply the delivery system. Typically, this is the air ducts or radiators that you are used to. The second part is something called a heat exchanger. This is the "Geothermal" unit that transfers heat between the air in your building and the water from the Earth. Finally, there is the piping that pipes water through the Earth. Pipes can be set up in either an Open Loop or Closed Loop System.

Briefly, a thermostat in each zone sets the desired temperature (just like it does in your house). When you are cooling your building the geothermal heat pump passes hot air, from the building, over lots of little tubes of cold water. Of course the cold water cools down the hot air. (The Earth below you holds the water at a relatively constant temperature that is usually between 50° and 60° in the United States.) Do you see how efficiently cold water naturally cools hot air? A traditional system would take the hot air and try to forcefully push it out of the house into the hot summer air. Do you see why so much energy is required?

In Winter, when you want to heat your building, the geothermal unit takes cold air out of the building and again passes it over lots of tubes of the Earth water. This water, still between 50° and 60°, now is warmer than the cold air passing by it and again naturally transfers the heat from the water into the air. Once again we are efficiently passing heat between hot and cold. A traditional system would try and take the cold air out of the house by throwing it outside into the cold winter air. Again, do you see how much work is needed to push cold air into even colder air?

That's the beauty of geothermal. Fundamentally, all it does is take air from the building at one temperature and transfer heat in one direction or the other, depending upon whether you are heating or cooling, with water that flows from the ground. The sun is actually supplying all the energy for the heating and cooling. The only energy you really put in is the small amount of electricity to run your fans and circulate your water.