A ground loop is the mechanisum by which the heat is extrated from the ground. All land has a residual temperature of approximately 6 degrees. By passing very cold liquid throught a long pipe in the ground in the form of a loop it is posible to extract this residual heat. The heat is the concentrated by the heat pump for use in the home. The ground tempreature will over a period of time drop producing a sink of coldness.

The liquid in the pipes is specially prepared mix including anti-freeze so there is no possiblity of the pipes expanding and cracking if they freeze. The pipes are layed in a specially perpared trench about 2 meters below the surface, lined with sand. The pipes are then coiled over the sand before being covered with sand and gravel abd back filled.

In summer, the ground around the pipes has been cooled by the heat pump after heating the house through the winter. By running the fluid in the ground pipes through a simple cooling coil built into the inlet duct of the heat recovery system (see comfort cooling & air conditioning); the whole house can be cooled for the cost of running a circulation pump. This cool fluid can also be sent into the underfloor heating pipes to give additional cooling if required, and/or one room can be cooled - like a gym, a larder, or a wine cellar.