Can a heat pump cool a house? It depends, say the experts and here's why

While there's not a straightforward yes or no answer to 'can a heat pump cool a house', there are certainly ways of achieving both temperatures from one unit. However, it's not simply a case of flicking a switch say the experts.

Choosing the right type of heat pump is essential and the only way to ensure you have the dual functionality you want. Why? Not all heat pumps work in the same way and even though some models can do both, they may not be the right choice when upgrading an existing heating system.

The good news is, you do have options and once you understand them you can decide the best system for heating and cooling your home all year round.

Choosing the right type of heat pump

Although the term heat pump is used in a generic way, there are a number of different types of heat pump which is why there isn't a simple yes or not to the question, 'can a heat pump cool a house'.

And while the answer to can a ground source heat pump cool a house is yes, it's not quite as simple when it comes to air source heat pumps.

While not all air to water heat pumps can cool a house, air to air heat pumps do have the functionality to provide both hot and cold air flow.

But, they aren't without some risks. Not many air to air heat pumps can also heat water, which means it might not always be the best solution to your needs.

How do heat pumps cool a house?

If you're weighing up heat pumps vs air conditioners you could in fact avoid needing to install both if you choose well. The basic fact is that an air to air heat pump is essentially an air conditioning unit that works in reverse.

"An air-to-air heat pump operates in a similar way to a fridge," explains Hamid Salimi, residential product manager at Daikin UK. "It exchanges energy from the outdoor air, and air-to-air heat pumps cool the space by the process of refrigerant evaporation and condensation.

"In heating mode, an air-to-air heat pump absorbs energy from the outdoor air and releases it as heat through the indoor unit. In cooling mode, the process is reversed: heat is extracted from inside your home and released outside," he explains.

Andy Pattison, head of renewables at BOXT confirms that, "many people don’t realise is that air conditioning units are technically air-to-air heat pumps, so while in warmer months they remove heat from inside and release it outdoors, in cooler months they can reverse their operation to keep you warm.

"However, not all air source heat pumps can do this," he warns, "so it’s important to check the make and model carefully before making your choice. If you're uncertain or want to know more, the company you choose for installing your air source heat pump should guide you through your options when providing your initial fixed quote.”

Hamid Salimi

Hamid Salimi has a BSc and MSc in mechanical engineering and has worked with Daikin for over 13 years in various roles such as product applications, HVAC design and currently as a Product Manager leading a team of product specialists covering all aspects of residential renewable heating.

Andy Pattison

Andy Pattison is Head of Renewables at BOXT with over 40 years of experience in the heating and renewables industry. He has held this role for the past three years.

New build installation vs upgrading

That said, it's not impossible for air to water heat pumps to cool a room too. Some have a reverse function which means they can also provide colder temperatures. But, they may not be the best solution if you are considering upgrading your current heating system, warns Andy Pattison.

"While both types of air source heat pumps are technically capable of offering cooling, we would typically recommend that an air-to-water heat pump should only be considered for cooling if it’s being installed in a new build home where it can be factored into the building design.

"This type of heat pump requires correctly installed underfloor heating or fan coil units, and wouldn’t work with the radiators that most UK homes have.

"However," adds Andy, "air-to-air heat pumps are much simpler to retrofit and can offer both heating and cooling in one or multiple rooms of your home."

Heating and cooling vs hot water supply

If you are assessing if your home is suitable for an air source heat pump, you'll also need to take you hot water supply into account, as well as your heating and cooling needs.

While air to air heat pumps have historically not been designed with hot water supply in mind, companies are recognising the need for solutions that cater to more than just heat. And with rising temperatures becoming an issue for us all, the juggle between hot and cold is increasingly becoming part of the discussion.

Companies are starting to recognise the growing need for products that fulfil a number of different needs, with Daikin's all-in-one system, Multi+ a prime example of the changing face of heating systems.

"Offering heating, cooling, air purification and domestic hot water for small and mid-size homes, it connects to five units and one domestic hot water tank," explains Hamid Salimi. "The unit is compatible with a 120 and 230-litre tank and a wide range of indoor units. The outdoor unit is compact, which means that it is ideal for small outdoor spaces such as balconies and terraces."

But, with a limit still on the space it can heat and cool, if your home is larger, you may still find it makes more sense to install air conditioning and ensure you have plenty of other measures in place to keep a room cool too.

So, while the answer to can a heat pump cool a house can be yes – if you choose the right one – it's certainly a decision that needs plenty of consideration and discussion with your supplier before you make any final choices.

It's likely the cost of air conditioning and air source heat pump costs will also be a contributing factor when picking your system, but with the current Boiler Upgrade Scheme potentially expanding to offer grants for air conditioning too, assistance to do both may soon become easier than it was.