heat pumps

Heat pumps work by drawing heat from the ground or other heat stores at low temperatures, and using this to expand a refrigerant fluid in a closed circuit. The refrigerant is pumped through a condenser, where it transfers heat into your heating circuit. The principle is the same as a fridge, working backwards.

A ground source heat pump needs an electricity supply to drive the pump. It is considered a sustainable technology because the amount of heat provided to a building is typically 3-4 times the amount of electricity needed to drive the pump - so the system is effectively 3-400% efficient.

For ground source heat pumps you will need space to run an underground plastic pipe circuit outside the building. This can either be in a horizontal trench - typically running about 2m underground, or in one or more vertical boreholes, which can be 50m or more deep.

The ground is not the only heat source that a heat pump can utilise. Water sources such as a river or a lake are especially good as the temperature of water is relatively high and stable. Air is another source of low temperature heat that can be used and there is no a wide range of heat pump designed on the market for this purpose. Generally air source heat pumps are cheaper and easier to install than either ground or water systems but the efficiencies obtained tend to be lower.

Heat pumps work best with underfloor heating, because they are most efficient providing slightly lower-temperature water. This means they are most economic when installed in new commercial buildings. Systems can qualify for reduced VAT, Enhanced Capital Allowance and government grant aid.

In the summer the ground temperature is cooler than the outside air temperature. Some heat pumps can be reversed and used as a cooling mechanism, drawing heat out of a building. This can considerably improve the cost/benefit of a heat pump system in buildings that have a cooling demand.

Our site assessments and surveys will size a pump (and if applicable a ground circuit for your needs) and give you a cost/benefit analysis for this specification.