Air source heat pumps

Running Costs –
Annual running costs will be significantly lower when compared to conventional methods such as gas and oil.

Environmental Risk –
This electrically powered system means there is no need to store fuel on site.

CO2 Emissions –
No onsite emissions as no flu is required.

Maintenance –
Simple to maintain and built with good quality materials.

Investment –
The moment you install an air source heat pump you are saving money. Our systems are three times more efficient than a conventional electric boilers and offer paybacks of 4-7 years.

How do air source heat pumps work?

Heat from the air is absorbed at low temperatures into a fluid within the heat pump. This fluid then passes through a compressor where its temperature is increased, this heat then transfers to the heating and hot water circuits of the property via radiators or underfloor heating.

There are two air source heat pump systems available;

Air to Water

This system uses a wet heat emitter such as under floor heating or radiators. The temperature provided by the heat pump is lower than conventional forms of heating such as gas and oil meaning the heat emitter must be sized correctly to ensure the building is comfortably heated.

Air to Air

Air to air source heat pumps use ducting throughout the property to distribute warm air. This is achieved by a fan blowing air through a heat exchanger supplied by the heat pump.

Is an air source heat pump suitable for me?

  • The heat pump will need to be located externally with 1.5 metres of free space in front and roughly 0.5 metres to each side. This allows air circulation to the unit which is crucial for performance and reflects on running costs.

Any heating system will perform more effectively if the building it provides is draft proof and well insulated. This is even more important when using a heat pump as the flow temperatures are often lower.

The heat pump will replace your existing boiler. How quickly it returns your investment depends on which fuel type you replace. Gas and electric replacements offer the quickest paybacks followed by oil depending on its cost at any time. In most cases you could see you money returned within 4-7 years.

Underfloor heating is the best choice when combined with a heat pump due to its large surface area being ideal for distributing the lower flow temperatures. If radiators are used it is important to ensure they are sized correctly. You will often find that some radiators around the house will need changing.

The installation cost varies dependant on whether you are installing to a new build or introducing to an existing system, with the latter being slightly more expensive.

Cost & Savings


Installing a typical air source heat pump system will cost between £6,000-£12,000. The cost depends on the size of the property and heat loss of the building. The running costs also depends on these factors as well as the way you use you heating system.


You will always save money when converting to a heat pump; how much you save depends mainly on your existing fuel type. To increase your savings and return on investment the following should be considered;


  • Heat emitter – Underfloor heating is ideal but not always possible. If using existing radiators they must be sized correctly. Isle – eco will undertake a detailed heat loss calculation to ensure the correct capacity is installed and radiators are sized correctly.
  • Fuel costs – Unfortunately there will still be a fuel bill to pay as the heat pump uses electricity to operate although at a much higher efficiency and lower cost. In some cases solar photovoltaic can be used to run the heat pump.
  • Replacing older boilers – Savings will be higher when replacing an old existing boiler as its age often reflects its efficiency.
  • Controls – They way in which the heat pump is designed and controlled are important and can vary from system to system. Understanding how your system is controlled will guarantee a sharper performance with more cost effective results.


Our heat pump systems come with a three year warranty as standard. We also offer extended warranties of five and seven years at an additional cost. Our workmanship warrantee covers all work undertaken for two years from the date of commissioning.

You can expect the system to operate effectively for 20 years providing regular maintenance is undertaken; this is also required to qualify for all warranties. All our clients are given an installation and maintenance handbook which should enable the end user to undertake minor maintenance works such as cleaning debris from the inlet grille and checking pressure and flow rates via gauges located on the system.

An anti-freeze is used within the system to prevent freezing at the external unit. The concentration of anti-freeze will need to be monitored and changed every 3-5 years to ensure adequate protection.

Planning permission

Installing a ground or air source heating system will not require planning permission providing:

  • The property is not registered as a listed building or place or a potential listed building or place
  • In the case of an air pump where the installation is to be located on a principal elevation, the building is not in a conservation area
  • The highest point of the installation must be no more than 2.5 metres above ground level
  • Noise emanating from an air pump must comply with the noise rating curve equivalent to the background level measured 1 metre from the boundary of the nearest residential premises. The background level is the A-weighted sound pressure level of the residual noise in decibels exceeded for 90% of the time
  • No previous permit stated that permission is required.