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).
Open Loops
In an open loop application, the system brings water up from
one location, the water then passes through the heat exchange process at the
heat pump, then is discarded in another location (up flow from the draw in
location).
There are several variations of the open loop application.
Single-well open loop with drainage field
Standing-column wells (only possible with fractured
bedrock)
Double-wells
Some examples of each of these is shown below
Single-well open loop w/drainage field
Standing-column well
Double-wells
Surface water system
Closed Loops
In a closed loop application, the system consists of plastic
piping which is completely sealed.
The pipe is filled with a fluid that is continuously re-circulated
without ever contacting the earth.
This closed loop must travel enough distance so that the full heat can be
transferred, this distance will depend on the soil quality as well as the size
of the heating or cooling system.
There are four different closed-loop configurations to
ensure proper length for heat transfer:
Horizontal
Spiral (aka slinky)
Vertical
Submerged (pond or lake loop)
Back to "How Does GeoThermal Work"