How does an air source heat pump work?

Air source heat pumps (ASHP) are being talked about more and more.

It’s no surprise with low emissions and low running costs and attracting potential income through the UK government’s Renewable Heat Incentive (RHI).

But how does an ASHP work?

Can you get heat from thin air?

The short animation below shows you how:

Outside air  is drawn into the ASHP, The air gives up this heat at the heat exchanger, The heat from  this air turns  refrigerant  liquid into  gas at  very low  temperatures, The warm gas is compressed by the compressor. This makes it hot, The hot gas gives up this heat at the heat exchanger, The water from your central heating system takes up this heat and heats your house, The now liquid refrigerant is cooled through the expansion valve ready to start again, This process repeats until your house is warm and toasty.

If you are interested in finding out more about the benefits and costs of installing air source heat pumps, get in touch at

One thought on “How does an air source heat pump work?”

  1. Our air source heat pump has been in operation for five months, over spring and summer, so it is a good time to review the performance and efficiency of our Caernarfon 18kW Eco Air Source Heat Pump (ASHP) from Global Energy Systems.

    Most ASHP owners in the UK use Mitsubishi, Hitachi or Daiken ASHPs, so it should be interesting to see how a British manufactured ASHP, made for the British climate, will perform and compare.

    As part of this video, I’ve addressed our coefficient of performance (COP), performance and efficiency, the control panel and settings for the ASHP, noise rating and some general thoughts.

    I will do a follow up video in autumn and winter to provide a full performance and efficiency comparison.


    Additional information and data sheets:

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