Tel: 01483 750447

Manor Way Industrial Estate, Manor Way, Woking, Surrey


Why use an air source heat hump?

The benefits of air source heat pumps are similar to ground-source systems in that they use a renewable source of heat (the outside air for ASHP and the ground for GSHP). Also the systems run on electricity, which eliminates the need for a gas connection or storage of oil/solid fuel. However Air source heat pumps present tremendous advantages over ground source heat pumps because they are much cheaper and require much less space to install.

Instead of requiring the disruption and excavation cost of buried underground coils, air source systems can be fitted to an external wall and require much less total installation time.

How does an air source heat pump work?

An air source heat pump only needs a heat source (the outside air), two heat exchangers (one to absorb and another one to release heat) and a relatively small amount of drive energy to keep the system going.  A heat pump extracts thermal energy from the environment.  In the case of an ASHP the source is the outside air. The pump extracts the energy at a certain temperature, increases that temperature and then releases it into a medium which in the ASHP system is the water running to your low temperature radiators (or standard radiators sized at a lower flow temperature), under floor heating system or fan coil units. Between those two media the heat is moved by means of a working fluid.

Is an air source heat pump suitable for my home?

You should consider the following issues if you're thinking about installing an air source to water heat pump.

The external unit can be fitted to an outside wall or to a location within 75 metres of the internal unit which means that it can be hidden out of sight if necessary

A 'low temperature' air source heat pump can easily cover the total heating requirements of a well insulated property but due to the lower temperature compared with traditional boilers, it is essential that your home is insulated,draught proofed and These measures will lower your heat demand and make the system more effective.

Consider what fuel is being replaced: if it's electricity, oil, Liquid Petroleum Gas (LPG) or coal, the payback period will be very fast. With the seemingly never ending increasing cost of gas the payback period will also become less and less for this fossil fuel as years go by.

The type of heat distribution system. Air source heat pumps can be used to heat water that is circulated through radiators but under floor heating is more effective due to the lower temperature produced. Air-to-air systems require indoor fans to circulate the warm air.

If you want to further reduce your home's CO2 emissions and save even more energy you can install a solar PV or wind turbine system to provide the primary energy to power the compressor and pump. We provide this as an added option See “HEAT PUMPS AND RENEWABLE PRIMARY ENERGY” page of this website.

How much do Air source Heat Pumps cost?

Air to Air Heat Pumps

Obviously there is a range of costs depending on the size of the rooms and the property but single rooms can be treated from approx £1400 upwards to about £4000 for 3 bedrooms and £6000 - £8000 for a whole 6/7 room house. The added benefit with the air to air heat pump is you will get cooling in the summertime from the same equipment.

Air to Water Heat pumps

Sizes of systems will range from 6KW for a two bedroom house or apartment to 16 KW for a large (5-6 bedroom) house. The capital costs for design, supply and installation will be in the range £6000 to £12000 and will provide all of the heating and hot water needs of the home. In our view the ideal combination is an air to air heat pump in bedrooms (gives quiet summertime cooling also) and an air to water system for the ground floor rooms and for low cost hot water

Running Costs

These will vary from property to property and the fossil fuel currently used to provide heating and hot water. However energy savings from 30% – 60% are possible. The following table gives an indication of the potential savings for an average detached property where an air source to water heat pump provides 100% space heating and hot water.

Can an Air source Heat Pump be connected to other renewable sources?

When used in conjunction with renewable energy sources (Solar Hot water, Solar PV and/or wind turbine) there is potential for zero cost or even negative cost (sell all surplus energy back to the Grid) heating and hot water with the corresponding substantial reduction in CO2 emissions. See the Heat Pumps and Renewable Primary Energy section of this website.