How it works | Commercial Heat Pumps

Heat pumps have some impact on the environment as they need electricity to run, but the heat they extract from the ground, air, or water is constantly being renewed naturally.

Ground source heat pumps (ground to water) use buried pipes from 1.2m and below to extract heat from the ground or from vertical bore holes drilled as deep as 500 metres. It circulates a mixture of water and antifreeze around the buried ground loop. Heat from the ground is absorbed into the fluid and then passes through a heat exchanger into the heat pump. The ground stays at a fairly constant temperature under the surface (average 10°C), so the heat pump can be used throughout the year - even in the middle of winter.

Air source heat pumps (air to water) extract heat from the outside air in the same way that a fridge extracts heat from its inside. It can get heat from the air even when the temperature is as low as -25° C . The heat from the air is absorbed at low temperature into a fluid. This fluid then passes through a compressor where its temperature is increased, and transfers its higher temperature heat to the heating and hot water circuits of the building, it is particularly suited to low temperature systems such as underfloor heating and fan assisted radiators.

Air source heat pumps require less space than ground source and are ideal for domestic, commercial and industrial installations. The relatively mild UK climate in many regions, allows air source heat pumps to approach the performance range of ground and water source heat pumps, with a reduced installation cost. But Air Source Heat Pumps can be more efficient over the heating season depending on the location, type of unit used and application. For example a high efficient Air Source Heat Pump installed in Penzance on under floor heating would be more efficient than a Ground source heat pump installed using horizontal ground collectors. This is because the mean air temperature is greater than the mean ground temperature for a system designed to IGSPA standards.

Water source heat pumps extract heat from water. The heat is absorbed at low temperature into a fluid. This fluid is passed through a compressor where its temperature is increased, and transfers its higher temperature to the heating and hot water circuits of the building. The year round availability of water at temperatures between 7°C and 12°C make aquifers, lakes and ponds attractive sources of energy for heat pump technology, particularly if the water quality is high enough for it to be circulated directly through the system. Environment agency consent may be required for extracting water.

Reversible Heat Pumps

A reversible heat pump provides all year round heat, plus cooling in summer. Reversible heat pumps can be air, water or ground source.

For heating a reversible heat pump uses conventional refrigeration technology to extract the energy stored in the environment and raise it to a temperature suitable for space heating and hot water. In cooling mode reversible heat pumps can be passive or dynamic. The high energy costs of air conditioning and the negative effects on employee performance of an overheated building make the cooling effect of a reversible heat pump particularly attractive.