Air Source Heat Pumps

Benefits of air source heat pumps

By installing an air source heat pump you will be:

Cutting your energy bills. Air source heat pumps are powered by electricity so you can cut your gas, oil or solid fuel usage. Savings could be as much as £700 per year.
Increasing your energy efficiency. Air source heat pumps are considerably more efficient than electric radiators.
Reducing your carbon emissions. Depending on the fuel you are replacing you can save up to 5 tonnes of CO2 per year.

Types of air source heat pumps

There are a number of air source heat pumps available:

Air to water heat pumps. These heat wet heating systems and create hot water using the heat from the air.
Air to air heat pumps. These collect air from one place and use fans to distribute it in a warmer state to another place that needs heating.
Heat recovery. This does either of the above functions but does so by collecting warm air from an indoor space with too much heat (loft, kitchen) instead of outside.

1. Air to water heat pumps

An air to water heat pump usually includes an external unit collecting heat from the outside air temperature. This heat is then transferred to the internal unit which uses the refrigerant cycle to transfer the heat into a wet central heating and hot water system.

The benefits of air to water heat pumps

Great for urban properties or properties with no space for ground source loops.
Easy to retrofit than ground source suiting older properties, especially those with oil or LPG boilers.
Soft-start inverter-driven heat pumps have much lower running costs than their older predecessors.
Certain models can reach higher water temperatures of 65 degrees enabling better use with radiators.

Some points of caution:

Performance fluctuates as air temperature fluctuates.
Slightly higher running costs than ground source or lake source heat pumps.
Location choice is still important to avoid anomalies affecting performance.

Potential applications

Air to water heat pumps are an excellent application for new builds with good insulation. Because of their potential for achieving higher output temperatures they can also be considered for houses with normal radiators.

If you live in a rural area and rely on oil or LPG to heat your property then you could see large savings from converting to an air source heat pump.

2. Air to air heat pumps

Air to air heat pumps take air temperature from internal or external units and transfer the heat via an air distribution system.

External units can be used to heat apartments or open plan rooms such as church halls, offices etc. and also work alongside or integrated with air conditioning systems.

The benefits of air to air heat pumps

Single unit systems can be easy to install and lower cost than air to water.
Great for open plan rooms or apartments.
Fast acting.
Heat and cooling options available.
Gets heat into the spaces you need it and not just up the walls and into the ceiling.

Some points of caution:

Energy use fluctuates as air temperature fluctuates, which is why inverter driven heat pumps are more cost effective.
It is important to understand air movement within the building so as not to expect too much from the heat pump.

Potential applications

Air to air heat pumps are particularly good at heating open plan spaces. This can include old or new buildings such as churches, town halls, offices, meeting rooms and halls, exhibition halls.

3. Heat recovery

Heat Recovery is a kind of air to air, or air to water heat pump, whereby the warm air from excessively warm areas of a building (kitchens, lofts) can be used to warm water or air.

Benefits of heat recovery

Makes use of excess heat in buildings which increases COP versus.
Great for small apartments or buildings with high excess heat areas.
Can be used for heating or hot water.

Some points of caution:

Heat recovery is better suited to new builds or buildings where ductwork can be visible.

Potential applications

Heat recovery can be used in kitchens, lofts, conservatories or areas with large solar gain that can be used for heating hot water or heating systems.

The cost of air source heat pumps

Air to water heat pumps can cost between £6,000 - £8,000 and includes the internal and external units. Sizes range from 4.5-14kw on single phase electrical supply for domestic use.

Air to air heat pumps (not heat recovery systems) can cost from £2,000 - £5,000 installed for a 6kw unit.

More complex air to air systems which can heat and cool are sized and costed on a case by case basis.

Your savings

Heat pumps tackle your whole heating bill and are often twice as cheap to run versus traditional fossil fuel systems.

Heating and hot water can be around 50-60% of your energy bills and so by tackling this your payback will be much better.

Whilst the initial investment is expensive when compared to a conventional gas boiler, the payback is relatively quick.

Fuel Displaced	Savings per year	CO2 savings per year
Gas	£50	No saving
Electricity	£700	5 tonnes
Oil	£20	No saving
Solid	£460	4.6 tonnes

Savings are approximate and based on an air source heat pump providing 100% of space heating and up to 50% of hot water, with the additional 50% provided by electric heater, in a detached property. (Source: The Energy Saving Trust).

Your air source heat pump check list

There are a few considerations to help make the decision whether an air source heat pump is right for you:

Where do you want to position the external unit? The heat pump needs to be fitted to a wall or placed on the ground outside your house. It needs adequate space around it to allow for a good flow of air and for quality insulation to protect them from the elements.
How well insulated is your property? If you install a heat pump in a house with poor insulation and normal radiators your heat pump may be less efficient and potentially cost you a lot of money to run. It will also require additional mains back up power with an immersion heater.
What is the heating system you are using or planning to use the air source heat pump with? You can run heat pumps with radiators if they are large radiators or fan assisted. This means they can make better use of the lower temperature heat offered by heat pumps. In some properties we would recommend adding additional radiators once a heat pump has been installed to help those colder rooms.
What are you reasons for wanting to use an air source heat pump? There may be other suitable alternatives.

Next Steps

When you are ready, please call 0800 023 2326 or email us.

We are happy to provide advice over the phone and, provided your property is suitable, arrange a no obligation site survey to assess your property and surrounding land.

We recommend you commission and SAP report to calculate your heating load accurately.

You will need to confirm your local planning authority does not require planning permission.