- Low running costs
- 1kw of electricity to generate 4kw of heat
- Ideal for underfloor heating
- Can be used for heating or cooling
- Low maintenance
Air Source/Ground Source Heat Pumps
Ground source heat pumps extract heat energy stored in the ground, using either ‘slinky’ pipe buried just 1-2 metres below ground or vertical bore holes. The pipes contain an anti-freeze solution, which absorbs low-grade heat energy and carries the energy back to the heat pump. Here the refrigerant circuit transfers – or pumps – from low-grade to high-grade heat, via a compressor.
These ground source and water source heat pumps have a high coefficient of performance and designed and installed properly can use only 1kW of electricity to generate 4kW of heat output.
Slinky pipes require an area of land approximately twice as large as the total floor area of the house for them to collect sufficient heat without freezing the ground. If a large area of land is not available, bore holes would need to be drilled.
Air source heat pumps extract heat from the ambient air, even with temperatures as low as -5˚C and they can achieve flow temperatures of 58˚C. Collectors do not need to be buried and bore holes do not need to be drilled – so no expensive groundwork is necessary. They are larger units than the equivalent ground sourced machines, but they can be installed indoors or, more advantageously, outdoors. The UK enjoys a relatively mild winter climate and therefore air to water heat pumps can be considered for all the heating and hot water needs.