What is a Heat Pump? | heatpumphouse.com

In this guide:

A heat pump is an electric device that extracts heat from outside your home and transfers it inside. It creates power to run the heating and hot water cylinder in your home by converting heat absorbed from the air, water or ground. Heat pumps are incredibly efficient as they can provide more heat energy to your home than the equivalent electrical energy they use to extract heat.

Unlike gas and oil boilers, they don’t burn fossil fuels to produce heat, so, provided your electricity comes from renewable sources they produce no carbon to operate and are great for the environment.

The heat pump is primarily made up of three components; a fan, compressor and the circulating pumps.

Heat pumps are a relatively new technology in the UK but have been used in Europe for a while. Their popularity is on the rise in the UK as the government pushes to reduce greenhouse gas emissions.

They are expected to become a staple in UK households over the coming years. No new gas boilers will be sold after 2035 so heat pumps are expected to take over.

What is an air source heat pump?

An air source heat pump can extract heat from the air outside your home and deliver it into your property to heat your central heating system or the water in your hot water storage tanks.

A single air source heat pump can provide heat and hot water to your home. They tend to work best in environments where the outside and inside temperatures don’t vary too dramatically.

They are a great option if you have underfloor heating as the system doesn’t have to get as hot to create the same amount of heat.

If you’re changing over from a traditional gas boiler to an air source heat pump you may need to invest in some bigger radiators to make sure the pump can generate enough heat to keep your house nice and warm.

Although, you may be able to install a heat pump and use your existing radiators.

You’re likely to find that heat pumps take a bit longer to generate heat and make your home warm compared to traditional heating systems.

Are there different types of Air Source Heat pumps?

There are two main types of Air source heat pumps, Air to Water air source heat pumps and Air to Air air source heat pumps.

There is also the option of a hybrid heat pump which can be combined with an existing oil boiler or gas central heating system.

Hybrid Air source heat pump systems work to provide the basic heating and hot water and the existing heating system generally only kicks in to offer extra hot water or to offer an extra heat source in cold weather.

Air to water air source heat pump

The most common type of air source heat pump for domestic hot water and heat is an air to water pump. This type of system transfers heat produced into a wet heating system to give you central heating and hot water.

Air to Air air source heat pump

The Air to Air type pump only works like a central heating system and does not offer hot water. Often referred to as an air conditioning unit, this type of heat pump transfers the heat from the outside air inside the home to circulate. They can normally be switched between functioning as an air conditioner and a heating system.

How do Air Source Heat Pumps work?

Air Source heat pumps work differently from more traditional heating systems as they don’t convert electricity into heat or burn fuels. They don’t heat your home by generating heat themselves but instead extract heat from the air outside your home and the air pump transfers the heat inside.

Air source heat pumps are efficient as they deliver more heat energy than the electrical energy they use to operate which means they can often have lower running costs than more traditional ways of heating your home.

Air source heat pumps have outside units which contain a fan that uses outside air to power itself and run the heating system. It works by taking the air from outside and moving it into a refrigerated circuit where it gets compressed to a high temperature, it’s then transferred into the water with the heating system via a heat exchanger.

Air source heat pumps are easier to install than ground source heat pumps and are generally less expensive.

Can air source heat pump heat hot water?

Yes, air source heat pumps can be used to produce hot water. You will find that the water created from an air source heat pump will have lower temperatures than other hot water sources. You will want to make sure you have a big enough hot water cylinder to hold the amount of hot water that you need. Due to the water being a slightly lower temperature, you are likely to need to use more of it to create a higher temperature for things like washing up or running a bath rather than turning on the cold tap too.

How much do air source heat pumps cost?

Air source heat pumps are generally more expensive than traditional boilers and generally can cost between £4,000 to £8,000 just for the pump. You will then have to pay to have the heat pump installed which can bring the price to between £5,000 and £10,000 according to EDF.
As Air Source heat pumps work better with large radiators or underfloor heating, you will want to factor these improvements into your costs too. You may also need to consider adding extra insulation to make your home as energy efficient as possible (heat pumps aren’t great in poorly insulated homes).
The government will be offering up to £5,000 towards the installation of heat pumps from April 2022 which could make a big difference to the cost.

What are the Advantages of an Air Source Heat Pump System?

Air source heat pumps are very efficient for heating your home and providing hot water
Similar in price to other home heating system
Some government funding is available (with more likely in the future)
Low to no emissions – especially if on a no carbon tariff
Easier to install than ground source heat pumps
Good life expectancy
Can often offer heating and cooling functions
Very efficient to heat your home and heat water
Similar in price to other home heating system
Some government funding is available (with more likely in the future)
Low to no emissions – especially if on a no carbon tariff
Easier to install than ground source heat pumps
Good life expectancy
Can often offer heating and cooling functions

What are the Disadvantages of an Air Source Heat Pump System?

Don’t get the same heat from radiators as you would with some other central heating system
No immediate kick of heat
Installation is more complex than a boiler (can be between 3-8 days)
You need to have space outside to store the pump
Electricity is still needed to power the pump

How Effective are Air Source Heat Pump Systems?

The amount you will save on your heating bills by having a heat pump is different for everyone. Factors include :

How old the system you are updating is and what does it runoff
How big is your property is
How much hot water do you use
How much do you turn your heating on

The main draw for many people considering installing a heat pump is the lower environmental impact due to having a system to heat your home without having to burn fuel like natural gas or oil.

The government has said that it will look to introduce measures to ensure that heat pumps aren’t more expensive to run than gas boilers. And they are creating a new scheme from April 2022.

Ground Source heat pumps are expected to save much more money off your energy bill compared to a gas boiler or air source heat pump.

What is a Ground Source Heat Pump?

Ground Source heat pumps (or Ground to Water heat pumps, or geothermal heat pumps) use thermal energy (or heat from the ground) to power your heating system or provide hot water. Ground Source heat pumps work by transferring heat from underground into pipes through heat transference fluid in the pipes.

Ground source heat pumps offer the same features as a conventional boiler, so can heat hot water and radiators in your home, but instead of burning fuels, they use heat already available from the ground.

Here is what a ground source heat pump is.

Geothermal pumps use electricity to generate heat and are considered energy efficient as they use less electricity than equivalent boiler would to produce the same the heat.

Here is what geothermal heating is.

How do you install a ground source heat pump?

Ground Source heat pumps are more expensive to install than their air-source counterparts. One of the reasons they cost more is because of how difficult they are to install. However, they can be cheaper to run in the long run due to being able to take advantage of the ground temperature which can be pretty constant.

To install a ground source heat pump you generally need a fair amount of land around your property as the pipework under the property will take up quite a lot of space.

You will generally need quite a large amount of outside space that you are happy to be dug up for the heat pump installations. The larger the home you need to heat, the bigger the ground loop will need to be.

How does a Ground Source Heat Pump Work?

Ground source heat pumps use a network of underground pipes (known as a ground loop) and a heat pump above ground. They pump anti-freeze and water around the ground loop and naturally absorb heat from the ground.

Before giving off heat to your home, the water and anti-freeze mix is compressed and goes through a heat exchanger which will take the heat and transfer it to a heat pump.

You can use a ground source heat pump to power your central heating, your hot water and even underfloor heating.

Advantages of a ground source heat pump

They can be very efficient due to using less power than the heat that it creates
They can have lower running costs and cut your energy bills
You may get financial support from the government to install one

Disadvantages of a ground source heat pump

Ground source heat pump systems are expensive to install (can cost between £10,000 – £18,000 according to EST)
You have to dig up your garden
You need to have the space to have the heat pump outside
Better for homes with large radiators or underfloor heating systems
Electricity is still needed to power the pump

How much do ground source heat pumps cost?

Heat pump costs vary, Ground Source heat pumps are much more expensive and can range between £10,000 to £18,000. You may also need to consider the costs of extra insulation and any new radiator or underfloor heating system you may need as well as the labour to fit it.

What Kind of Heat Pump Should you Choose?

Generally, air source heat pumps are a little cheaper to install but offer slightly less efficiency than their ground source heat pump equivalents.

Newer air source heat pump models are also a little quieter than the early models.

Because ground source heat pumps are much more difficult to install and costlier to purchase, most UK residents will be better off with an air source heat pump with the exception of those with large grounds surrounding their property or plenty of money to have one installed.

Heat Pump FAQs

Can I get money towards a heat pump with the Renewable Heat Incentive Scheme?

The Domestic Renewable Heat Incentive (RHI) scheme offered applicants money towards home heating costs if you installed one of the following systems;

a biomass boiler
solar water heating
specific heat pumps

The government reimbursed applicants based on the amount of renewable heat that your heating system produced.

The scheme closed to new applicants in March 2022 but is being replaced by the boiler upgrade scheme from April 2022.

What is a Water Source Heat Pump?

Water source heat pumps work in a similar way to Ground source heat pumps only they extract heat from a body of water located near to your property.

Submerged pipes are needed to extract heat from the water which then bring the heat into your home within a fluid.

A body of water like a river, lake, large pond or even a series of boreholes drilled into the ground is necessary to install a water source heat pump.