What are air source heat pumps, and why are they so popular?

With the UK Government pushing air source heat pumps, it’s caused a lot of people to wonder what the fuss is all about.

Since the UK Government have set the target of becoming carbon neutral by 2050, there has been a huge rise in the use of renewable energy in the home.

In particular, air source heat pumps are a popular choice. But what are they, and why have they become the go-to for your home’s renewable heating solution?

The benefits of installing an air source heat pump are as follows:

  • They are more cost-effective to run as they use a minimal amount of electricity
  • They are energy efficient as they are low-carbon alternative to domestic heating
  • They can heat your home and hot water with the correct central heating system for your property
  • You may be eligible for the Boiler Upgrade Scheme, which can save you thousands on cost and installation

What are air source heat pumps?

In basic terms, air source heat pumps take heat from the outside air and convert it into heat, which is then used inside your home’s central heating system.

Let’s go a little more in depth so we have more of an understanding of how this process works.

Also known as an air-to-water source heat pump, an air source heat pump does just that: it takes air from outside your home and turns it into a liquid, which is then used inside your heating system.

By using electricity, the heat pump compresses gas collected from the outside air to turn it into water. This gas is called a refrigerant.

Once this refrigerant has been transferred into water, it then travels through your home through the heat exchanger, cooling down as it travels. Whilst it travels, the refrigerant expands and cools down further until it can absorb more heat from outside, beginning this process again.

The heat that is taken to the heat exchanger is what is used to heat your home through your central heating system. Whether that’s through radiators or underfloor heating, an air source heat pump can be used with multiple central heating systems.

Will an air source heat pump help me save on my energy bills?

Heat pumps are more energy efficient than other heating systems as more heat is produced than the amount of electricity used. Even though electricity is needed for the compressor and pump, not much is used compared to electric boilers for example.

Depending on the outside temperature during this process, different amounts of electricity will need to be used, so it’s difficult to determine specifically how much you’ll save on your energy bills.

You need to take into consideration the following when answering this question:

  • Which central heating system are you replacing, and how much does this cost you?
  • How much does your electricity cost you?
  • How efficient is your air source heat pump?
  • What’s the design of your current central heating system? Will changes need to be made in order to use an air source heat pump – for example, the size of your radiators?
  • What’s the outside temperature, and how does this fluctuate throughout the year?

Most standard air source heat pumps can help you save both on your CO2 emissions and energy costs.

Take a look at this graph on Energy Saving Trust* to view what you could possibly save.

Will I have to change my central heating system altogether?

This all depends on the current central heating system you use and your budget.

Standard gas boilers heat water to your radiators at 75-degrees Celsius. However, an air source heat pump circulates water to your radiators at around 35-45-degrees Celsius, depending on the outside temperature.

If you have radiators with a larger surface area, then more heat can be delivered to your room.

If you have smaller radiators, then your heat pump would have to work harder to deliver a higher heat output. This means that the heat pump would run less efficiently as more electricity would be needed to increase the water’s temperature.

To tackle this, you may want to replace your radiators with larger ones, or opt for underfloor heating, which is designed to be optimally used with air source heat pumps.

You could also run your heat pump at a higher temperature however, this may not be the most cost-effective option.

One of our MCS-certified engineers at Swale Heating can visit the property to recommend the best options for you and your current central heating system. Click here to contact us via our website, or call us on 0800 731 3344.

Where can an air source heat pump be installed?

Unlike the standard gas boiler, which can be installed indoors, air source heat pumps must be installed somewhere outside of your property. A unit is fitted to a wall or on the ground where flowing air is present in order for it to work.

There are two types of systems available: monobloc and split.

The monobloc system is usually cheaper and quick to install. It’s also usually smaller in size, making it less efficient.

The split system, on the other hand, can be installed inside your home and is normally larger in size. This system is more energy efficient because it’s of its inside installation. When heat is transferred, the system is usually warmer, making the inside of your home warmer as there is less heat loss. The split system can be more expensive than the monobloc system.

Swale Heating can help you make the right decision for your home and budget. One of our MCS certified engineers can visit the property to recommend the best system for you. Click here to contact us via our website, or call us on 0800 731 3344.

Can an air source heat pump be used for hot water?

In simple terms, yes. However, the water will be cooler, compared to a gas boiler, as the water is cooler.

This means, if you need a lot of hot water for when you’re running a bath for example, you’ll need more hot water, which means that you may need a bigger hot water cylinder.

You may also need to replace your current cylinder for one that is specifically designed to be used with heat pumps. These cylinders contain a much larger coil with a larger surface area, which enables the stored water to be heated quicker.

How must does an air source heat pump cost?

Again, this all depends on a few factors. Depending on the size of your property, the size of the air source heat pump itself and your current central heating system, costs can vary from £7,000 to £13,000*.

Thankfully, the UK Government have the Boiler Upgrade Scheme, which could get you £7,500 off the cost and installation of an air source heat pump.

If you own your own property, or are a landlord, you are eligible to apply for the BUS. 

You must have an installer advise which heating system is best for your property before they apply for the grant on your behalf.

Thankfully, Swale Heating can do just this as all our engineers are MCS certified and experts in renewable energy solutions. Click here to contact us via our website, or call us on 0800 731 3344 to find out more information about the services we offer.


Information sources:

*Energy Saving Trust