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Air Source Heating: What it is, How it works? (2023 Guide)

If you are wondering what air source heating is, how it works, and whether it is the right solution for you, you need to read this article. We will tell you the advantages, and disadvantages, and how much you can expect to pay for having the system installed for your home.

What is Air Source Heating?

The term air source heating might seem like an odd one. After all, the cold air outside is the reason most of us need to use heating in the first place. How can that air possibly be used to heat our homes?

The answer is actually using a simple and effective technology which is both energy efficient and good for the environment too. Air source heating is growing in popularity thanks to its relatively low upfront costs, green credentials, and the prospect of saving money on your heating bills.

In this guide, we will tell how you can use such a system to save money on your heating bills and lower your carbon footprint. We will also give you the lowdown on how much this system costs and how this compares to other types of heating system.

What is air source heating?

An air source heating system uses a system that works a little bit like a reverse refrigerator. The technology features a compressor and a condenser which can absorb heat from one place and release it in another.

With domestic heating, an Air Source heating system uses a heat pump to absorbs heat from the outside and releases it inside through hot air, hot water-filled radiators, underfloor heating or as hot water.

Air Source systems can do all the same work as a traditional gas boiler. They can keep your home warm in winter, cool in summer, and most systems will also supply hot water as warm as 80 °C.

They also use a minimal amount of electricity which means the carbon footprint of an air source heating system is much lower than those of a conventional heating system.

How does it work?

The main device used by an air source heating system is the air source heat pump. This is fitted to the outside of your home. Because it is not the most aesthetically pleasing of items, it is usually fitted to the side or the back of a property.

The air source heat pump itself looks like an air conditioning unit and is situated at ground-floor level of a property to facilitate easy access.

Here’s how the process works, explained in five simple stages:

  1. The air source heat pump sucks in air from outside to heat a liquid refrigerant.
  2. It then uses electricity to power a pump which compresses this liquid to increase its temperature.
  3. This is then condensed back into a liquid to release the stored heat.
  4. This heated liquid is then pushed around your home either through radiators or via an underfloor heating system. Any liquid that is left-over is used in a hot water cylinder.
  5. This stored hot water can then be used for washing, showering, or bathing.

It is a remarkably simple process. And while it cannot heat radiators or hot water to temperatures as high as a conventional boiler, it can still generate temperatures that are sufficient for most homes.

How much electricity does it use?

Eagle-eyed readers will have noticed that an air source heating system does use some electricity. You might think this undermines its green credentials but actually, these systems are very energy efficient. The precise level of energy efficiency will depend on which make and model of the system you choose.

The energy efficiency of an air source heating system is usually represented by a SCOP measure.

SCOP is a measure of heat energy output per kW of electricity. It stands for Seasonal Coefficient of Performance.

SCOP tells you how many kilowatts of heats is generated for every 1kW of electricity used. For example, an SCOP rating of 3.2 means that for every 1kW of electricity, the air source heating system can generate 3.2kW of heat.

Different types of systems

While the technology works in much the same way, there are actually two different sorts of air source heating systems. The main difference is what they heat up and what can do inside your home:

  1. Air-to-water heating system – These systems draw in heat from the outside and use it to power a traditional wet central heating system. This means the heat generated is used to warm hot water which then feeds radiators or underfloor heating. An air-to-water heat pump can also be used to generate hot water.
  1. Air-to-air heating system– These systems work the same way but instead of the heat generated being used to heat up water, it is instead spread throughout the home using fans or similar systems. An air-to-air heating system cannot be used to generate hot water.

Air source heating vs Ground source heating

If you have been looking into energy-efficient heating systems, you might have come across something called a ground source heating systems and wonder what that is and how it differs from an air source heating system.

There are actually a number of key differences you should know about:

  • Heat source – As the names suggest, an air source heating system takes heat from the air while a ground source heating system sources it from under the ground.
  • Installation – Sources heat from the ground involves burying lots of pipes underground. The excavation and groundworks involved take time and labour and as a result, the installation pipes for a ground source heating system are much higher.
  • Efficiency – Ground source heating systems are slightly more energy-efficient than air source heating systems. A typical air source heating system will have an SCOP rating of around 3.4 while a ground source heating system will have a rating closer to 4.2.
  • Incentives – The UK government’s Renewable Heat Incentive offers more money for ground source heat pumps than air source heat pumps. At current rates, you will get 20.89p per kW for a ground source heat system but only 10.71p per kW for an air source heating system. These figures can change though.

How does the price compare to other systems?

When investing in a new heating system, cost is a crucial factor for many people. If you are willing to pay a little more for an environmentally friendly solution, an air source heating system is a great option.

A decent air source heating system will cost, on average, around £7,000. When installation costs are considered as well, the total outlay is likely to be in the region of £10-12,000.

As you will see, this is a very affordable price when compared to other environmentally-friendly heating systems. But the gap in installation pricing between an air source heating system and an energy-efficient new heating system is also pretty stark:

The upfront cost of buying and installing a heating system is a big cost consideration but it isn’t the only one. Running costs are also a big consideration and over the lifetime of a system, these environmentally-friendly options can end up costing less.

A typical new gas combi boiler will cost around £900-1,000 a year to run. In comparison, a regular air source heating system with an average SCOP of 3.4 will cost in the region of £700 a year to run.

That is an average saving of £200-300 a year in comparison to a new boiler. If you are running an older, less energy-efficient boiler you are likely to see even bigger savings.

Another cost factor to consider is how much money you can earn from your new system through the government’s Renewable Heating Incentive programme.

The Renewable Heating Incentive

The Renewable Heating Incentive is a fantastic government programme designed to incentivise people to use renewable energy in their homes. It pays a set rate for any heat generated in the home using renewable technology.

The scheme is quite selective about what types of technology qualify for payments and air source heating is one of those that does. It is worth noting that it will have to be an air-to-water system, not an air-to-air system to qualify for payments.

Speaking of payments, the current Renewable Heating Incentive tariff for air source heating systems is 10.71p per kW.

Over the lifetime of the system this can amount to quite a considerable amount of money. There is certainly a chance that over its lifetime, an air source heating system could pay for itself.

But do bear in mind that the government can, and sometimes does, adjust the tariff amount that different technologies are eligible for.

Pros and Cons

There are plenty of reasons for investing in an air source heating system but also a number of obvious disadvantages too. Here is a brief summary of the main pros and cons:


  • Environmentally-friendly – Air source heating systems are much more environmentally friendly than traditional gas or LPG boilers. They only use a small amount of electricity and no other fossil fuels.
  • Simple Installation –Air source heating systems are much easier to install than other environmentally-friendly heating systems. This means they also typically have lower installation costs too.
  • Lower running costs – An air source heat pump costs less to run than a traditional gas boiler which means your energy bills will be lower.
  • Eligible for the Renewable Heating Incentive – The government will pay you a fixed rate for every kW of energy you generate using an air source heating system.


  • Noise – The condensers used by air source heating systems can be noisy and will also blow out cold air. This can be annoying if you are doing anything around the exterior unit.
  • Electricity – An air source heating system does use some electricity so it is not a totally carbon-free system unless you also source your electricity from a renewable resource.
  • Levels of heat – Air source heating systems do not always generate high temperatures. This means you may find you need larger radiators to warm your home. Some systems specify that they work best with an underfloor heating system.
  • Upfront costs – The biggest drawback for most people is the high upfront costs. In the long run, an air source heating system could work out cheaper than a traditional gas boiler, but you will need to pay more upfront to get these benefits.

Affordable alternatives

A lot of people will have got to this point in the article and be thinking this is all very well but the upfront costs of an air source heating system mean there is no way they could possibly afford one.

There is no denying that while these systems could well work out cheaper over the course of their lifetimes, you will have to find more money upfront to buy and install one.

If this is not possible for you, then unfortunately, that means you will have to look for an alternative system.

Air source heating systems are the cheapest form of renewable heating system currently on the market. If you want to install a new heating system for less, your best bet is a modern and energy-efficient gas boiler.

If the environment is a key factor for you too, it is worth bearing in mind that modern gas boilers are much more energy-efficient than they used to be.

If you combine one with a smart thermostat that allows you to control exactly when and which rooms are being heating, it is possible to be much more energy-efficient and save money while still using a gas boiler.

How to get a cheap energy-efficient gas boiler with low installation costs

If your budget means you have no option but to choose a new energy-efficient gas boiler, the good news is that there is a online installation company that is able to offer you a great deal on the boiler and also save you a ton of money on the cost of installation too.

Our recommendation would be to buy your new boiler through HEATABLE.

HEATABLE is an online boiler sales and installation firm that has shaken up the industry with its novel approach. It has low overheads, minimal marketing costs, but as a national installer, it can still get great deals from boiler manufacturers. All this means it is able to offer great savings and low prices to all its users.

Buying a new boiler with HEATABLE is easy. Just visit their website and fill in their online form to give them a few details about your home, your heating systems, and what you want from a new boiler.

You don’t need to submit any personal information and they will give you a fixed price quote for a wide range of top-quality boilers to suit your property. They offer huge savings on installation costs from their national network of fully-qualified heating engineers.

HEATABLE specializes in gas boilers, but LPG boilers are available too and they offer models from all the top brands including Worcester Bosch, Viessmann, Ideal, and Baxi.

HEATABLE also offers some great finance deals too. You can choose to spread payments over 3, 5, 7, or even 10 years. Their standard APR is just 9.9% but keep a look out for their regulat 0% APR deals too.

Don’t just take our word for it

If you want a second opinion on HEATABLE, there are no shortage of positive reviews about them on the internet.

The HEATABLE website features more than 500 5* ratings online, while on TrustPilot, HEATABLE has an impressive 4.7/5 score and 95% of customers rate their service as either good or excellent.


Air source heating systems are environmentally-friendly and cost-effective and are able to provide you will both domestic heating and hot water. They are simple to install and apart from using a small amount of electricity have no carbon footprint at all.

There are some downsides though, which we have detailed in this article. The main one is the upfront cost which is beyond the reach of a lot of people. We have explained how over its lifetime, an air source heating system can save you money.

But if the upfront costs are too high, we have also explained how an energy-efficient new gas boiler could be a better alternative. HEATABLE is the best place to go to find one of these and we have profiled them too.

Have you got an air source heating system? How does it work for you?

Is there anything you wish you had known before buying one that we have missed out here? Your feedback is really helpful to all our readers, so why not share your thoughts using the comment box below?

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