heat pumps
Heat pumps extract heat from the ground or air outside and bring that heat inside where it is used for heating. The pump is powered by electricity but the amount of electrical energy it uses to do this is only a fraction of the amount of heat energy it brings into your home, and so heat pumps are considered to be low-carbon technology.
A ground source heat pump uses pipes buried in the ground to extract heat.
Here's how it works:
- A loop of pipe, called a ground loop, is buried in your garden. The pipe can be laid coiled, flat or vertical
- An electric pump in your house circulates a mixture of water and anti-freeze through the pipe
- While the liquid travels around the pipe it is warmed by heat from the ground
- The liquid returns to the house and into your heating system (underfloor or warm air heating works best)
- The longer your ground loop, the more heat the liquid absorbs and the better the result.
You should be able to have this system, providing your garden is suitable for digging a trench or borehole and accessible to digging equipment. And because the ground temperature stays constant below the surface, it can work all year round.
For more information visit the
The Energy Saving Trust - Ground source heat pumps page
An air source heat pump extracts heat from the air outside - even at temperatures as low as minus 15°C. It then uses it to warm up water for radiators or underfloor heating systems or to warm the air indoors.
There are two main types of air source heat pump system:
- Air-to-water system - This uses the heat to warm up water - though not as hot as a standard boiler system would, so it's better suited to underfloor heating than conventional radiators.
- Air-to-air system - This produces warm air, which is circulated around your home by fans.
For best efficiency, air source heat pumps are most suitable for homes that are well insulated. You also need sufficient outside space for the pump itself in order to get a good air flow.
For more information visit
The Energy Saving Trust - Air source heat pumps page