Guide To Air Conditioning With Air Source Heat Pumps

Achieving thermal comfort all year round is essential for the enjoyment of your property. It’s also crucial to lowering your energy bills.

Despite the name, many air source heat pumps are capable of cooling as well as heating your property. That’s provided they have reverse functionality.

New to all things air source heat pump air conditioning?

The WhatPrice team has put together a complete guide on everything you need to know about using an air source heat pump (ASHP) for air conditioning.

Can air source heat pumps provide cooling?

In the UK, we find ourselves investing lots of money in making our homes warmer in the winter through the likes of insulation. While this is essential for lowering energy bills, if all that heat cannot escape during summer, it can make our properties feel too hot and humid.

Unlike other countries, it’s not common to have air conditioning installed in British properties either. This can soon cause frustration and even exacerbate certain health issues, not least when it comes to getting a comfortable night’s sleep during a heatwave.

But what if your heat pump could come to the rescue, by working to both heat your home in the winter and cool it during the summer months?

Opting for an air source heat pump with a reverse function will allow you to do just that.

Given the rising temperatures the UK has experienced in recent years, cooling your home with a heat pump could just be a game-changer.

Cooling functionality explained

Air source heat pumps can seem complicated, but how they work to provide heating and cooling is actually pretty straightforward.

Most of the time, a heat pump will bring heat from outside. Even during colder temperatures, there is still energy in the air to be able to create thermal comfort inside your property.

But, when the temperatures rise as we head towards summer, a heat pump can be made to work in reverse.

Depending on the model, a typical heat pump is capable of lowering the indoor temperatures of a property by 8°C-14°C compared with the outdoor temperature.

How cooling mode differs from heating

The cooling and heating modes in an air source heat pump (ASHP) work very similarly. The only difference is whether the refrigeration cycle is set to work in its standard direction or in reverse.

When a heat pump is working in its standard mode, it will bring heat from outside and carry it inside. The warm air will be circulated indoors so that your home maintains thermal comfort.

Of course, in summer, that additional heat isn’t needed. So, instead, a heat pump can be instructed to work in reverse, to extract excess heat from the inside and release it outside.

Do all models offer cooling?

No. Not all heat pumps offer air conditioning functionality.

The heat pump must have a reverse function, meaning it can bring heat from outdoors and also expel heat from inside your home when it gets too hot.

The best heat pumps which offer cooling functionality are air-to-air heat pumps. In some cases, air-to-water heat pumps can offer cooling if they have fan coil units installed.

If air source heat pump air conditioning is important to your purchase decision, you must discuss this with your installer. That’s because while modifications to allow cooling functionality to an existing heat pump are technically possible, it will ultimately be easier and cheaper to buy the correct heat pump for your needs to begin with.

Air source heat pumps vs air conditioning

No, it’s not just you – it’s been proven that heat does indeed ‘feel hotter in the UK’ than other countries! This is because of our relative humidity, which is higher than countries with dry heat.

So when it comes to creating a cool and calm environment in your home, you could choose either a traditional air conditioning system or an air source heat pump.

But which will offer the best solution overall?

Main differences in function

Both air source heat pumps (ASHPs) and air conditioning offer cooling functionality. However, how both appliances work is very different.

With the exception of advanced air conditioning units which also have heating functionality, most air conditioning only offers a cooling function. This means that in the UK especially, you would need an additional system to heat your home (i.e. a boiler), since air conditioning only cools.

Typically, air conditioning in the UK is only used during the summer months. It works by absorbing heat and moving it outside.

Unlike air conditioning, an air source heat pump can work either to bring heat indoors when it’s cool, or transfer excess heat outside during summer.

Which is more energy efficient?

If newly installed, both air conditioning units and air source heat pumps offer excellent energy efficiency.

However, the most overall efficient system is a heat pump, since it can work to both heat and cool your property. Heat pumps are also designed to be greener, and can generate up to 5kW of energy for every 1kW used.

Cost comparison – installation and running

Air conditioning has a cheaper upfront cost in terms of installation.

However, unlike with air source heat pumps, there are no government grants which cover the cost of installing air conditioning.

On the whole, air source heat pumps are cheap to run. Since air conditioning isn’t needed all year round, it can also have low running costs.

If you also get solar panels installed, the running costs of either system would also be reduced.

Overall, the total costs of a heat pump and air conditioning are not comparable. That’s because an ASHP will also replace your boiler and therefore, eliminate your gas bill in the process.

Heating and cooling performance

Air source heat pumps can heat and cool your home as required throughout the seasons. Heat pumps work to maintain an ambient temperature all year round, rather than providing blasts of heat or cool air. Specifically, they work to ensure that the temperature of each ‘zone’ of your property remains consistent, rather than being allowed to get too hot or cold.

Modern, newly installed air conditioning units boast excellent performance. However, older air conditioning units experience a reduction in efficiency and overall performance. This means that older systems will cost more to run and may not adequately cool your home.

Also, air conditioning is only designed to cool your property and cannot heat it. Therefore, you would require a traditional boiler to power your central heating, radiators, underfloor heating and hot water requirements in addition to air conditioning.

How effective is an air source heat pump at cooling a home in summer?

Air source heat pumps use reverse functionality to expel heat from inside, making them extremely effective at cooling your property in the summer.

An air-to-air heat pump is one of the best options to consider if cooling as well as heating is important as part of your heat pump purchase decision. In particular, a mini-split or multi-split system works just like a split air conditioning system.

It’s also possible to get cooling functionality from an air-to-water heat pump. However, the cooling will be slower and more subtle overall than an air-to-air system.

Cost comparison between a heat pump and air conditioner

As you might expect, there are some stark price differences between the cost of getting a heat pump installed vs air conditioning installed.

But before you rule out the higher cost of a heat pump (especially one which can also cool your property), it’s important to understand the true value to be gained from having one system which can do it all!

Installation costs comparison

The Boiler Upgrade Scheme Grant can reduce the cost of getting a heat pump installed from £11,000 to £16,000 to a cost of between £3,500 to £8,500.

Installing air conditioning is much cheaper, with a UK average of between £550 and £2,000 according to our research.

However, the main caveat to consider here is that air conditioning can cool your home, but it cannot heat it. Instead, using a heat pump for cooling can eliminate the need to get air conditioning installed. Since a heat pump will also replace your boiler, the higher upfront cost is more cost-effective than it seems.

Which is cheaper to run: a heat pump or an air conditioner?

Most sources we’ve checked are in agreement that a heat pump is indeed cheaper to run than air conditioning. This is especially the case for a heat pump air conditioner – AKA a heat pump capable of both heating and cooling your home as part of the same system.

On average, UK homeowners pay between £800 and £1,800 per year to run a heat pump.

The costs of running an air conditioning unit can vary depending on its energy efficiency, how often it’s used and the energy costs during the usage period. The typical running costs can range from 24p to £1.23 per hour of operation.

What we also know is that when a heat pump is used for heating, it can be 3-4 times more efficient than an electric heater. A heat pump is also cheaper to run than a gas boiler so long as your property is well insulated.

Since heat pumps can also provide cooling by working in reverse, this also promotes excellent efficiency and lower running costs. This is especially the case when compared to running multiple systems, i.e. a boiler to heat your home and a separate air conditioning unit to cool it.

💡You may also like: Air Source Heat Pump Installation & Running Costs

Installation and maintenance

There is no such thing as universal ASHP installation, since it very much depends on the age and size of your property. Plus, your current heating system, radiator sizes and available space for the required outdoor unit and indoor hot water cylinder.

The good news is that heat pumps aren’t difficult to maintain. Though, learning how to operate a heat pump can involve more of a learning curve compared with a boiler, as there are a few more controls to get to grips with.

What to expect during installation

Before getting an air source heat pump installed, your installer will conduct a pre-installation survey to iron out all of the details we’ve just touched on.

However, a major benefit of this survey is that you’ll be better prepared for what to expect. Plus, you are more likely to achieve long-term satisfaction with your heat pump, since it will be sized correctly for your property.

On average, air source heat pumps require 2-5 days to install. The installation itself will require a small team of people, including one team member who is an electrician.

The first step of the installation will be to disconnect and remove your existing heating system (i.e. a gas combi boiler).

Depending on the specifics of your installation, the new outdoor unit, indoor unit, hot water cylinder, radiators and pipework will then be installed. This also includes the electrical aspects of the installation, so that all units are correctly powered up.

Once everything is in, the entire system will be tested and flushed. Any settings will also be configured, and your installer will also run you through how to work your new air source heat pump.

The final steps involve registering the warranty and ensuring you receive a copy of the MCS certificate.

Regular maintenance requirements

Yearly servicing is key to maintaining the health and overall efficiency of a heat pump. However, there can also be some maintenance steps that users need to perform too.

About once a month, the air pump filter will need cleaning. After every three months, this filter will require replacing.

Also, if using an air pump for cooling, this can mean the filter requires cleaning more regularly.

During colder weather, you will also need to check that snow or ice doesn’t form on the outside unit to prevent blockages. Other seasonal debris such as leaves or branches will also need to be removed from the heat pump.

Beyond this, if you notice any unusual sounds coming from the heat pump, or if the heat pump experiences any performance issues, then you will need to schedule a repair without delay.

Lifespan and warranty coverage

Most heat pumps have an expected lifespan of 15-20 years, which is considerably longer than that of a boiler.

The warranty period will vary depending on the manufacturer, though the average range is between 5-7 years.

Most heat pumps also come with a 2 year manufacturer guarantee as standard. However, Aira offers a guarantee that your home can maintain temperatures of between 18˚C-22˚C all year round for 15 years, or you’ll receive free repairs.

Air source heat pump cooling FAQs

Have more questions about heat pumps for heating and cooling? We’ve answered some of the most popular queries below.

For anything else, be sure to check out our other heat pump guides where we cover the typical installation costs and much more.

How many degrees can a heat pump cool a house?

Model dependent, a heat pump can cool a house by around 8°C-14°C below the outside temperature.

Heat pumps are not designed to offer the aggressive cooling of an air conditioning unit. However, they do work to maintain an ambient temperature in your home all year round.

Therefore, if you get an air source heat pump installed, you shouldn’t experience extreme temperature highs or lows. Instead, the temperature will feel more consistent throughout the seasons.

Can I replace my existing heating and cooling system with a heat pump?

Yes. In most cases, a heat pump is designed to replace both your heating and cooling requirements. Specifically, in a way that’s more energy efficient and is ultimately cheaper to do compared with a traditional boiler.

To make an ultimate determination, your installer should visit your property to conduct a professional assessment. That’s because in some cases, the heat pump you choose, plus the level of insulation your property has can make replacing other systems with a heat pump more challenging.

Ultimately, if your property does require any upgrades, it’s likely worth doing these to be able to totally replace your heating and cooling requirements with a heat pump. It will mean you’ll save money and it’s also a great way to future-proof your property.

Will I need a backup system during extreme temperatures?

Make no mistake that a heat pump is designed to work all year round, whether your home requires heating or cooling. So no, you shouldn’t require a backup system.

Most air source heat pumps operate at temperatures between -25°C and 35°C. For most areas of the UK, this range is perfect.

However, there are certain areas of the UK such as the Scottish Highlands which experience more extreme temperature fluctuations. In this case, the type of heat pump you have, plus the quality of your property’s insulation could mean a backup system is required.

On the whole, cold climate heat pumps (CCHPs) offer the best protection against the need for any backup system in colder weather.

But since this page is about air conditioning with a heat pump, it’s good to note your system will be able to cope when things get toasty in the summer. According to the Met Office, the UK has only experienced temperatures exceeding 38°C four times in the last 20 years, which should offer peace of mind.

Can I control my heat pump remotely or with smart devices?

Controlling your heat pump remotely can ensure that by the time you get home, your property is sufficiently cooled in the summer and likewise, heated in the winter.

So long as your heat pump offers the necessary functionality, including WiFi and smart device connectivity, you can control everything with just a few taps of your phone. However, you will need to check the compatibility of smart integration before you purchase a heat pump.

Beyond ensuring thermal comfort, remote or smart controls can also help monitor your energy usage over time.

Studying the data is useful to help manage your energy bills, especially if you are more used to the running cost fluctuations (i.e. in the winter vs summer costs) of a traditional gas boiler.

Air source heat pump cooling FAQs

Have more questions about heat pumps for heating and cooling? We’ve answered some of the most popular queries below.

For anything else, be sure to check out our other heat pump guides where we cover the typical installation costs and much more.