How do heat pumps work?

Heat pumps are an excellent means of saving on your energy bills.

Both air source and ground source heat pump systems are far more efficient than your typical means of heating, not to mention far more renewable and better for the environment.

Heat pumps are a significant part of Scotland’s drive to a net-zero emission economy by 2045, require little maintenance, and will save you a small fortune on energy costs.

They come in a few different variations, but ground-source and air-source heat pumps are the most common.

The pumps, used both commercially and domestically, have skyrocketed in demand in 2021. Rated People’s Home Improvement Trends Report found a 28% rise in installations this year.

The report stated that around 3% of UK homeowners own a heat pump, but the figure is expected to spike this year.

The UK government has even pledged 600,000 heat pumps to be installed around the country by 2028, though some industry experts believe this is too ambitious.

With heat pumps rapidly becoming more popular, we wanted to talk about how they work, given that many people are unsure.

Heat exchange

The heat source will either be external air or water collected underground, depending on whether you have opted for a ground source heat pump or an air source heat pump.

It is then either blown or pumped over the heat exchange surface of the heat pump.

The heat is then used to change the refrigerant liquid’s state to a gaseous form.


The gas then goes through a compressor, increasing the temperature of the gas. If you have ever inflated a bicycle tyre with a pump, you will have noticed how the pump gets warmer.

This is due to compression. While heat pumps are far more complex in design, they have similarities in functionality compared to a bicycle pump.

Heating the building

The heated gas is passed over the internal heat exchange surface and is then either blown through the building, transferred to the central heating system or the hot water system.

The gas then goes back to its liquid state as it falls in temperature, and the refrigerant returns to the heat exchange surface, where the process continues until the building has been heated sufficiently.

And that’s it. If you are new to heat pumps, you may have been surprised at how the process works.

It’s probably not quite as complicated as you may have thought at a glance, which is one of the things that makes heat pumps so desirable.

They are simple but are virtually limitless in their efficiency and what they can provide.

If you would like to know more about heat pumps, contact us for more information.