How does it work?

A heat pump works by driving a working fluid around a refrigeration circuit containing four elements:

• Evaporator

• Compressor

• Condenser

• Expansion valve

The working fluid changes from liquid to gas (evaporates) as heat is absorbed from the heat source. Later in the cycle, the working fluid condenses to liquid as heat is released to where it is needed.

A heat pump can be used for cooling with the addition of a reversing valve that reverses the direction of the fluid and so the direction of the heat transfer. The central component of the heat pump is the compressor. This is usually driven by an electric motor, although gas engine driven compressors are also available.

There are three main parts of any heat pump system:

• A heat source and the means of extracting heat

• The circuit of working fluid within the heat pump itself and a power source

• A distribution system to deliver the energy in the required form.

It is necessary to include a power supply to the compressor to drive the heat pump. It is usually an electric motor which drives the compressor, but a gas engine is used in some designs.

Sunskai can help you design an integrated system which will maximise your use of solar energy to minimise the cost of your heating and domestic hot water requirements.