Air Source Heat Pumps

What Are Air Source Heat Pumps?

Think of an air source heat pump as a 'reverse fridge'. 

Heat is absorbed from the outdoor air and is compressed to raise the temperature. This then works to heat your home and hot water.


An air source heat pump is made up of an outdoor and indoor system. The outdoor system should be placed somewhere with good air flow and preferably in a sunny spot to help your air pump run more efficiently when the sun is out. The indoor unit is usually no bigger than a standard boiler. 

Air source heat pumps can be installed as one of two varieties:

Air-to-Water Heat Pumps:


These are the most common in the UK, transferring the heat into water which can then be used for traditional home heating elements.


 Air-to-Air Heat Pumps:


These work with a circulation system to heat the air itself.


Only air to water heat pumps are included in the Renewable Heat Incentive scheme and available for funding through either the ECO scheme or Green Homes Grant. 

What Are The Benefits Of An Air Source Heat Pump?

The main benefit of an air source heat pump is a more energy efficient method of heating your home, and therefore lower heating bills and carbon emissions.


This efficiency also brings a great saving on your carbon footprint of between 2,150 to 2,250 kg of carbon a year, compared to an A-rated boiler according to the Energy Saving Trust

If you are torn between an air source or ground source heat pump, then air source are considerably easier to install, and on average cost about a third less to install and need considerably less outdoor space.

They have been around for a long time and are a very reliant technology. As above they are very similar to a fridge and they do not break down often.

Will An Air Source Heat Pump Work For My Home?

Air source heat pumps offer a great alternative to gas & oil boilers but to work at their best your home needs to be a well insulated home.

If you are looking to spend money on a new heating system but insulation in your home is not up to standard, an air source heat pump would not be a sound investment for the future.

Air source heat pumps work best at producing heat at a lower temperature than boilers so if you have an draught proof home this will increase the efficiency. 

It is also worth keeping in mind that while it is possible that if you are changing from a boiler to an heat pump that you could use the existing pipework and radiators, this is not guaranteed and some or all may need to be replaced.

One potential drawback of an air source heat pump is because of the lower temperatures produced it can affect the maximum tap water temperature that your home can achieve.

Cost And Available Funding Options

The cost of an air source heat pump is dependent on a number of factors, such as model installed, size, performance/efficiency and any potential additional works needed such as pipework and radiators.

The average cost is between £7000-£15000 and you may see your annual energy bills increase by £75-£100 to run an air source heat pump.

However, as a sustainable alternative, and with help the RHI Scheme and the Green Homes Grant scheme to recompense for the initial outlay of expense for installation, it’s an attractive option for those considering their home’s contribution to carbon emissions. 

RHI tariffs continue to stay very attractive and a 4 bed property could see a payment of around £1600 per year. RHI payments continue for 7 years after installation.

If you use the Green Homes Grant to help with the initial cost of installation, this will be deducted before you receive an RHI payment. 

Assignment of Rights Funding

Assignment of rights lets an investor fund the purchase & installation of a renewable heating system in your home and in return receives the rights to the RHI payments over the course of the seven years. The Investor and the property owner must ensure certain obligations are met to ensure ongoing payments of RHI.

Important Key Information:

  • The homeowner owns the system not the investor so it will not stop the sale of your property. If you decide to sell your home you would simply let the investor know and the new owner would assign the RHI payments to the current investor.

  • You assign the RHI payments to the investor during the Domestic RHI application process. 

  • You must follow the Domestic RHI rules. This is crucial for both you and the investor to ensure ongoing RHI payments.

  • The obligations include the regular maintenance and servicing of the Air source heat pump (with our partners agreement this is included with the installation for 7 years) and making sure that if the Heat Pump or meter needs to be changed that the investor and OFGEM are made aware.

  • For consumer protection, the investor will need to be a member of either the Renewable Energy Consumer Code (RECC) or the Home Insulation and Energy Systems Contractors Scheme (HIES). Additionally, the investor must be registered as an investor with Ofgem.

  • You need an up-to-date EPC taken no more than 24 months ago to qualify for the Domestic RHI. If your EPC recommends loft, floor and/or wall insulation, make these improvements and get a new EPC before applying.

You can download Ofgem’s free guide to RHI and Assignment of Rights here: Guide to RHI and Assignment of Rights.pdf

If I Am Interested What Should I Do Next?

If you are interested in having an Air source heat pump installed please click the 'apply button below and complete the form. We will discuss the options available to you and if you want to go ahead arrange for a surveyor to contact you to arrange a free survey.

Once completed and if you are happy to continue then it is matter of arranging the ECO3 grant, assignment of rights agreement and/or payment and picking a date for install.