The ground that surrounds us provides a fairly constant source of heat with only small seasonal variations which reduce with depth. Ground Source Heat Pumps generally work by extracting this heat from the ground in the winter and using it for central heating, but systems can also be designed to transfer heat the other way returning heat back to the ground thus providing domestic cooling in the summer.

The heat from the ground is collected by a fluid passing through a system of pipes either laid horizontally 1-2m down below the frost line, or vertically in bore holes where space is at a premium. This warmed fluid then has the heat “extracted” from it in a similar process to that used in a refrigerator, and this “concentrated” heat is then used in the central heating system.

It should be noted that it is generally only possible to raise the temperature of the central heating water to about 30º centigrade which is ideal for under floor heating systems but too cool to power conventional radiators. An important financial consideration for those looking to update their existing heating systems using this technology.