Heat Pumps

How It works

Outside air is a gas and therefore above absolute zero therefore it contains heat. An air source heat pump moves this heat into (or out of) your home as needed.

The three main components of a heat pump are:

  • Heat exchangers that extract heat from the air outside and deposit that heat into the air inside.
  • A compressor which raises the temperature from the outside air.
  • A Means to transfer heat into either a hot water tank or heating system like radiators or underfloor heating tubes.

The process by which the pump operates involves changing the state of a refrigerant gas within the system of heat exchangers and heat can be pulled in from outside and moved inwards. The only energetic input into the system from the pump is the compressor and the rest is simply the result of simple thermo-dynamics to do with changes in pressure of gases and liquids causing changes in temperature of their surroundings.

Air vs Ground Source Heat Pumps

There are two main types of heat pump. The ground source and the air source heat pump. The Air source uses latent heat within the air to heat the building it is in whereas the ground source makes use of the fact that earth, due to its hot core emits radiation as heat and this heat is contained largely under the ground.

A Ground Source Heat Pump is relatively unobtrusive and more consistently efficient since the temperature of the ground varies a great deal less than that of the air and it tends to have a longer life span since far less of it is exposed to the elements.

The process involves digging bore holes or burying a system of pipes underground and requires that you own enough land for the process to be carried out. It is therefore ideal for farming communities and landowners in general.

Air source pumps on the other hand require mainly space within a building rather than the land around it. The air source pump looks like an air conditioning unit with the added bonus that it can be used to both heat and cool your home. While more reliant on outside temperatures Air Source Pumps still produce at least three times the energy they consume.


You could save up to 45% on your heating bills and CO2 emissions. An air source heat pump can have a life span of 15 years or more and so any installation will more than pay for itself.

Savings can be highly dependant on the system being replaced.

Not recommended for Gas systems.

Savings from the Energy Savings Trust Savings from typical system.