Back

Ground-Air Source

Heat pumps are machines that move heat from one location to another. Like a fridge moves heat from inside to outside, a heat pump moves heat from outside to inside your home or building. The heat moving technology inside a fridge is the same as that in a heat pump.

What are heat pumps?

Heat pumps are used for heating, cooling and hot water provision. They are an alternative to fossil fuel burning systems such as gas and oil boilers. As described above they use a refrigerant circuit to move heat from outside to inside your building. Heat pumps have been in use for heating for over 60 years: the Royal Festival Hall is a well known example of this from the 1950s. For more information see the following sites:

What are the benefits?

There are several benefits of using a heat pump rather than a fossil fuel burning system:

  • If your home is well insulated, then a heat pump, which produces lower temperatures than a boiler, is likely to cost less to run, especially if used with under floor heating or a warm air delivery system. Heat pumps are very efficient, typically around 300%, this is because the amount of heat it produces is more than the amount of electricity needed to run it. This is measured by the coefficient of performance (CoP), which you will see in the details about any heat pump
  • In addition to lower running costs, CO2 emissions are reduced, and according to the Energy Savings Trust a typical saving is 1.8 tonnes per year when replacing oil burning systems
  • If you produce electricity from a PV or wind turbine, then this can offset or in some cases cover entirely the electrical consumption of a heat pump making it carbon neutral

How does it work?

The actual process inside a heat pump, which moves the heat from outside to inside is the refrigerant cycle. This cycle is a circulation of refrigerant by a compressor through an condenser, expansion valve and evaporator. During the above cycle the refrigerant absorbs the heat from the heat source, which is the natural warmth of the ground, or the ambient heat in the air outside.

For a more detailed description see the following websites: