A Guide to Heat Pumps

With households being urged to replace their old gas and oil-fuelled boilers in a bid to lower carbon emissions, you may have spotted heat pumps getting a bit more attention in the media recently.

But what are they, how do they work, and what are the benefits? Here’s our rundown of everything you need to know. 

What is a heat pump? 

In basic terms, a heat pump is a piece of technology that captures heat from outside, and transfers it into your home. Although electricity is required to do this, the heat energy delivered to your home is much greater than the electrical energy used to power the system - making it an efficient means of producing heat.

What are the different types of heat pump?

There are two different types of heat pump: ground source heat pumps, and air source heat pumps.

Ground source heat pumps

A ground source heat pump system harnesses natural heat from underground. To do so, water mixed with antifreeze is pumped through a network of underground pipes, absorbing the naturally-occurring heat stored in the ground. This is then passed through a heat exchanger, to extract the heat and transfer it to the heat pump, before being passed on to your home heating system. 

Air source heat pumps 

With an air source heat pump, the heat is absorbed into a liquid refrigerant from the outside air. This warms up the refrigerant, turning it from a liquid into a gas. The pump then compresses the gas to increase its temperature, before passing the hot gas through a heat exchanger and, as with a ground source heat pump, into your home. 

How do I decide what type of heat pump is right for me?

It’s always worth getting tailored advice from a professional heat pump installer before making a decision on what type of pump to get. 

However, generally speaking, the Energy Saving Trust advises that if you have a garden or large area of outside space (that you don’t mind digging up!), you might want to consider a ground source heat pump. Air source heat pumps, on the other hand, are a more common all-round domestic heat pump, and are suitable for many types of home.

How energy efficient are heat pumps?

Although both types of heat pumps require electricity to run, they are still a very efficient way of heating your home because the amount of heat they produce is considerably more than the amount of electricity they require to run. 

How much does it cost to have a heat pump installed?

Unfortunately, the large upfront cost associated with heat pumps are one of the major downsides to this technology. Currently, an air source heat pump can cost between £8,000 and £15,000 to install, whilst a ground source heat pump is estimated to cost upwards of £15,000. 

Can using a heat pump help me save money on my bills?

Most figures suggest that heat pumps will save you money in the long-term if you are using them as a replacement for non-renewable energy systems, such as electric storage heaters, oil, or coal. 

The Energy Saving Trust also notes that, with energy prices increasing, “we expect that heat pumps will become the cheapest as well as the lowest carbon form of heating available.”

That said, it’s worth consulting an installation expert and then doing your calculations, as there are a number of factors that will determine exactly how much you could save, including the energy tariff you are currently on, the design of your central heating system, and your location and its average air or ground temperature throughout the year.

Do many homes in the UK already have heat pumps installed?

In spite of their enormous potential to lower emissions, heat pump uptake in the UK is very slow, particularly when compared with European countries. According to figures from the European Heat Pump Association, the UK came joint-last for European heat pump sales in 2020; just 1% of UK households had heat pumps installed up to the end of 2020, compared with 60% of Norwegian homes and 43% of Swedish households.

However, with the Government recently announcing its ambition to see 600,000 heat pumps installed each year by 2028, the UK could be set to begin catching up. Speaking to the Evening Standard towards the end of last year, a Government spokesperson said that “We are confident that the upfront costs will fall in the coming years, and we will look to help the market drive down these costs.”

I’m thinking about having a heat pump installed. What next?

Although most heat pump installations are considered ‘permitted developments’, meaning no permission is required to have one installed, it’s always worth checking beforehand to make sure you don’t need to apply to your local authority for permission. The Energy Saving Trust has further information on installing renewables here.