4 to 30 -Years
|For those interested it operates in a similar way to a refrigerator working in reverse, it works on the principle of the vapour compression cycle within the pump. There is a volatile fluid known as a refrigerant. The refrigerant in the evaporator is heated by the heat source this causes it to turn into a gas. The gas then passes through the compressor; the compressor increases its pressure and causes its temperature to rise. The hot gas then moves to the condenser where it is condensed back into a liquid and in doing so it releases heat into the house via a distribution system. The refrigerant is then allowed to expand back to a low pressure through the expansion valve and pass back to the evaporator where it repeats the cycle in a closed loop.
What are they?
There are three main types, these are:-
- Ground Source Heat Pump (GSHP),
- Water Source Heat Pump (WSHP), and
- Air Source Heat Pump (ASHP)
They function by extracting heat from the ground the water or the air respectively and releasing that heat energy at a higher temperature within a building. All heat pumps consume energy usually in the form of electricity to operate the pump that is required to transfer the heat. They can supply all the heating you would require, and ground source systems are the most effective. To compare the performance of heat pump the term coefficient of performance is used (COP) and it described the ratio of heat movement to energy input. In the table below the Best Average COP is used. This a seasonal average, since air source and water source vary in performance with the temperature of the environment. For ground source the underground temperature is however remarkably constant all year.
It should also be noted that you will need a reasonable amount of land for an effective GSHP, unless you drill down, and for a water source heat pump a body of water is essential!