A short answer to this
question to give you a frame of reference would be like an air conditioner or
refrigerator. If you place your
hand behind either one of these appliances, you will feel warmer air. What they are doing is pulling the heat
from the inside and depositing this heat outside. It is then pulling in outside air and cooling it using a
compressor.
With a GeoThermal application, instead of using air, it is
using the constant temperature of the soil and water in the earth. So instead of blowing warmer air out,
it is moving the warmer air to a water loop which them deposits this energy
into the ground for air conditioning.
For heating a home, the opposite process takes place.
For this process you do need a way to move the heat between
your home and the earth. So, you
will have a water loop moving the heat between the two.
The major components of a GeoThermal system are:
The ground loop is the component of Geothermal which
exchanges the heat between the Earth and your home heat pump. Ground loops are also referred to as
Earth-coupled heat exchangers.
There are three categories of ground loops; open-loop, closed-loop, and
direct-exchange (DX). (for more
info click here)
While the ground loop exchanges the heat between the earth
and your home heat pump, the heat pump transfers heat between the ground loop
and the conditioned spaced of your home.
There are some basic thermodynamic principles which guide this
process. (for more info click
here)
Your soil and ground conditions refer to the type of soil
available in your area as well as the mean earth temperature in your area. Heat transfer principles apply here and
will tell you how long or deep your ground loop must be. There are some areas where GeoThermal
may not even be applicable. (for
more info click here)
Two of these you have control over, the third (your soil
conditions) you do not.