Ground Source Heat Pumps (GSHP) are used to extract heat from the ground. As the pump is situated underground, it circulates a combination of water and antifreeze fluid around the loop of pipe which is known as the ground loop.
Heat from the ground is then absorbed into the fluid which passes through the heat exchanger then into the heat pump.
As the underground holds relatively the same temperature it means that the ground loop can still absorb the heat right through the winter months.
The length of ground loop needed depends on the size of the home and the area of ground around it. The longer the length of ground loop, the more likely to absorb more heat as it is covering a greater surface area.