Ground source heat pumps use buried pipe collectors to extract heat from the ground which is used to heat conventional radiators or underfloor heating systems as well as domestic hot water. The heat pump circulates a mixture of water and antifreeze around a loop or loops of pipe. Heat from the ground is absorbed into this fluid and is pumped through a heat exchanger within the heat pump.
Low grade heat passes through the heat pump compressor and is concentrated into a higher temperature. Ground loop fluid, now cooler, passes back into the ground where it absorbs further energy from the ground in a continuous process while heating is required.
Beneath the surface, the ground stays at a fairly constant temperature, so ground source heat pumps can be used throughout the year – even in the middle of winter with high efficiency.
Heat pumps have some impact on the environment as they need electricity to run, but the heat they extract from the ground is constantly being renewed naturally. Unlike gas or oil boilers, heat pumps deliver heat at lower temperatures over much longer periods. This means that during the winter they may need to be left on 24/7 to heat your home efficiently but with little impact on running costs. It also means that radiators should never feel as hot to the touch as they would do when using a conventional boiler system.