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The Ultimate Guide to Air Source Heat Pumps

The Ultimate Guide to Air Source Heat Pumps

Air source heat pumps are rising in popularity all over the UK, and the rising cost of heating fuel has a huge role in this trend. Air source heat pumps are a great alternative to conventional heating and are a great way to save on heating expenses. There currently over 9,000 air source heat pumps units installed in the UK, and the number keeps on increasing. But before you decide to go for one, you have to make sure that your property is suitable for this form of heating. There are also some fundamentals you need to know about these types of heat pumps to make sure that you buy the right one for your needs. Here’s a quick beginner’s guide to air source heat pumps so you can make a more informed decision.

What are Air Source Heat Pumps Exactly?

What are Air Source Heat Pumps Exactly

The way air source heat pumps work is simple. These kinds of pumps will usually be installed at the back or side of a property. What they do is collect outside air and raise the temperature using a heat pump. The pump will need to use electricity to run, but it should use less than the heat being produced.

Air pumps will use the air collected outside to heat up a refrigerant. In most cases, the refrigerant used will be R410. The liquid will then be compressed using electricity and condensed back to liquid form in order for heat to be released. The heat is then distributed to underfloor heating or radiators, with the excess heat being stored using a hot water cylinder in many cases.

The Different Types of ASHPs

When it comes to ASHPs, two types dominate the market: air-to-heat and air-to-water units.

Air-to-water units collect air from the air outside your house and transfer it to a wet central heat system. However, since the heat generated through these systems will usually be lower than your traditional boiler, you may have to install larger radiators around the house or larger radiant floor heating units to compensate for this fact.

But one major benefit of these units is that they qualify for the RHI, which will allow you to get money rewards to cover for renewable heating additions to your home.

Installing an air-to-water unit may be cheaper on new construction projects than in existing homes, however. Adding this kind of system in the new building’s specifications will cost significantly less than having to retrofit an old building. Air-to-heat systems, on the other hand, are much less versatile and will not allow you to heat water, for instance. What they do is collect heat from the air outside of your house and redistribute it using fans, which might not be the best option for everyone.

If you want to learn more about heat pumps, and underfloor heating, in particular, you can find more information on heat pumps here. Incognito heat is a company that specialises in heating solutions and is a great resource for anyone looking for the best heating option for their property.

Running Cost for Air Source Heat Pumps

The period it will take to make your money back on the cost of installing a new unit will depend on various factors. Things like your RHI benefits, how efficiently the system is working, electricity costs, what type of system you were using before, and how the heat generated by this new system will be used will all have an influence on how long the payback period will be.
For instance, if you are replacing an old LPG boiler with a G rating, you can expect to save anywhere between £1,145 and £1,350 per year. But if you are switching from an outdated electric storage heater, the savings should be around £800 and £900 per year.

How does the Installation Work?

Air source air pumps look similar to a traditional air conditioning unit. One of their benefits is that they are much less intrusive than ground source pumps since they won’t require any digging to be done in your garden, so they might be a better solution for people who are looking for a more discreet option that won’t affect how their landscaping looks.

Another advantage is that they are much cheaper to install than many other heat pump models. And they can be installed much faster too, which is another major plus. According to the Energy Saving Trust, the average cost for an ASAP installation is around £6,000 to £9,000 for a regular unit.

One benefit specific of air-to-air units is that they can be used in reverse during the hot summer months. You’ll be able to use your air-to-air unit just as you would an air conditioning unit and use it to cool down your house. So, while air-to-air units might not be the best idea if you have to deal with particularly harsh winters, they can be a great option for more moderate climates and eliminate the need for adding both units.

What are Some of the Pros and Cons of Air Source Heat Pumps?

What are Some of the Pros and Cons of Air Source Heat Pumps

While air source heat pumps have tons of things going for them, they aren’t always the best option for everyone. For one, while the installation is much less disruptive than some of the other options, air source heat pumps can take up a lot of space in your garden. Another disadvantage of these units is the noise. Air source heat pumps can get very noisy, especially as they get older, which could be an inconvenience. This is why it’s important that you consider where you install them for them to be less of a nuisance as possible.

Not only that, but these types of units will need to be in operation 24/7 during the winter months. This could not only add to the noise but have a huge influence on your energy costs as well.
Another issue with these heat pumps is that they take significantly more time to heat up. This could leave your home very cold in the morning, especially if you commonly have to deal with sub-zero temperatures. It’s also essential that any house fitted with an air source heat pump is properly insulated.

However, air source heat pumps are much more energy efficient in most cases and they generate much less CO2 as well. So, they make the perfect addition for anyone trying to make their house greener. And they can also significantly raise the value of your property as a result. In addition, the fact that they are eligible for RHI kickbacks is another reason why so many people go for them.

While they can take some space, they take a lot less space than units that require fuel storage. They’re also a much safer option compared to other heat sources. Since there is no combustion involved, there is also no risk of explosions. Furthermore, air source heat pump systems reduce the risk of dangerous gases being emitted and do not require flues.

They’re also very versatile and can both provide heat and cold air depending on the season, plus they demand much less maintenance, further driving their cost down.

What about Maintenance?

In most cases, air source heat pumps will come with a two or three-year warranty. In addition to that, workmanship warranties will also cover you for up to ten years in some cases. Many manufacturers will also allow you to extend your warranty if you need extended coverage. Extended warranties will often be offered completely free of charge by certain manufacturers.

The person responsible for the installation should give you all the information needed on how and when maintenance checks need to be performed. This will not only make sure that your unit works optimally but it will also increase its longevity. It’s also very important that you ask your supplier what these maintenance requirements are in greater detail before you even consider installing the heat pump. For instance, you’ll likely have to perform annual checks on things like the inlet evaporate and grill to make sure that they are free of debris. You’ll also have to make sure to remove any plants and weeds growing there.

Your supplier will most likely advise you to check your pressure gauge on your central heating regularly. If they do, make sure that they walk you through the procedure, so you’ll know exactly what to do. The main goal is to make sure that the heat pump won’t freeze during the winter months. You might have to add antifreeze to the refrigerant in order to do so. Your supplier should be able to give you the exact concentration of antifreeze needed to prevent freezing.


Air source heat pumps are a great way to reduce your energy costs and can also reduce your carbon emissions significantly. If you think they could be the solution for you, you should consider working with an expert today to see how you could benefit from them.
Do you already have one? Let us know in the comments.

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