If you’re considering an alternative method to provide heating and hot water to your home, while reducing your heating and fuel costs, then an air source heat pump system could be worth looking at.
On this page
- What is an Air Source Heat Pump?
- What Are the Benefits of Air Source Heat Pumps?
- Types of Heat Pumps
- Costs and Savings
- Grants and Financial Support
- Calculate the System Size for Your House
- Things to Consider
- Find an Installation Company
- Questions to Ask
What is an Air Source Heat Pump?
An air source heat pump (ASHP) is used to provide a home with heating and hot water. An ASHP absorbs heat from outside air in the same way that a fridge extracts heat from its inside. This heat is then used for heating radiators, underfloor heating systems, or warm air convectors, as well as providing hot water.
Air source heat pumps can get heat from the air even at temperatures as low as -15°C.
How Does an Air Source Heat Pump Work?
An air source heat pump works by absorbing heat the outside air at a low temperature into a fluid, which is passed through a compressor, to increase its temperature. The most common air source heat pump is an air to water system, where the higher temperature of the fluid is transferred to the heating and hot water systems in a property.
What Are the Benefits of Air Source Heat Pumps?
There are many benefits available when utilising an air source heat pump system:
- The cost of running an air source heat pump to heat your home is considerably less than most alternative methods, such as oil, liquefied petroleum gas (LPG), or conventional electric heating.
- An air source heat pump has a low carbon footprint as it uses a natural source of renewable energy.
- The energy you generate with an air source heat pump can be used to heat your home and provide hot water.
- Having an air source heat pump will remove the need for fuel deliveries if the house is off-grid and has no mains gas.
Types of Heat Pumps
As well as air source heat pumps, there are other alternatives, such as:
- Ground source heat pumps: Using the earth as a heat source, ground source heat pumps utilise the stable temperatures in the ground to supply a property with heat and hot water.
- Water source heat pumps: These are similar to air source and ground source heat pumps but take heat from relatively consistent temperatures found in a body of water, such as a lake, river or stream.
- Solar-assisted heat pump: This system combines thermal solar panels with a heat pump in a single integrated system.
Costs and Savings
There are various factors to consider to calculate how much an air source heat pump will cost and what it could save you.
How Much Does an Air Source Heat Pump Cost?
The estimated cost for the installation of a standard air source heat pump system will vary due to several factors including the size of your space, how well insulated the property is, the way you use your room and what temperatures you wish to reach. Therefore, we would always recommend that you obtain quotes from a range of reputable and accredited installers. Click here to find accredited HIES members in your area who could help with your project.
What Could You Save?
The savings you could achieve will depend on several factors. Utilising underfloor heating can be a more efficient heat distribution system than radiators, as it doesn’t require the water to be heated to such a high temperature.
Electricity is required to power an air source heat pump, so you will still have fuel bills, but these may be much lower than with your current system. Also, if your current heating system is inefficient, you will more likely experience reduced running costs with an ASHP.
Once you have installed an air source heat pump, it’s important to learn how to get the most out of it through the control system. Although it might be necessary to set the heating to be on for a longer period, it’s possible that you will be able to set the thermostat to a lower temperature and still feel comfortable.
Air Source Heat Pump Efficiency
Air source heat pumps deliver heat at lower temperatures over much longer periods, unlike oil and gas boilers. At colder times of the year, you may have to keep the heating on continuously to properly heat your property. Improving your home’s insultation will help retain heat and reduce the energy needed to warm your rooms.
The lower the temperature the air source heat pump is working at, the more efficient it will be and therefore will use less electricity to run.
Grants and Financial Support
Boiler Upgrade Scheme
The Boiler Upgrade Scheme looks to reduce the cost of low carbon heating technologies, such as heat pumps, so that they are more affordable for consumers to buy and run. As part of the Boiler Upgrade Scheme, a £7,500 grant will be available for air source heat pumps for those who meet the eligibility requirements. Find out more here.
Calculate the System Size for Your House
An air source heat pump comes in various sizes. The size that is right for your home will depend mainly on two things – the size of your house; and how efficient your house is at keeping heat in. To calculate the correct size for your property, this usually involves the installer carrying out a room-by-room assessment of your home.
The installer will calculate the size of each of your rooms along with the material fabric of the walls and details of any windows. It would normally take the installer 1-2 hours to undertake this which will help identify the size of air source heat pump that is right for your property.
Things to Consider
- Efficiency: The Coefficient of Performance varies between different air source heat pumps. The higher the Coefficient of Performance the more efficient the air source heat pump will be.
- Noise: Air source heat pumps are not silent. They produce a noise similar to an air conditioning system. While not overly loud, it’s best to avoid placing them too close to bedrooms or neighbouring properties.
- Planning permission: Air source heat pumps usually don’t require planning permission as they’re typically listed under permitted developments. However, for this to be the case, certain criteria must be met, mainly in relation to the neighbouring properties. It’s always prudent to check with your installer and planning authority before you begin any installation.
Cylinder
To get the best out of an air source heat pump system, it is necessary to install a suitable cylinder. This has a much larger coil capacity than a standard cylinder, allowing it to heat a greater surface area.
Underfloor Heating
Underfloor heating is an ideal way of getting the maximum efficiency out of an air source heat pump system. Pipes are installed underneath floorboards for the hot water to flow through, heating your home to a comfortable temperature. Underfloor heating can be more efficient than radiators as the water doesn’t need to be so hot. You will need to ensure that when installing underfloor heating that the pipe spacing isn’t wide, as this could create cold spots on the surface and you may need to turn the temperature up which reduces the efficiency of the air source heat pump.
Radiators
Air source heat pumps work better at lower temperatures, and this means that they are most effective when used in conjunction with larger radiators. It is possible to use standard-sized radiators, but this requires heating the water to a higher temperature, which reduces the system’s overall efficiency.
Find an Installation Company
You should always choose a reputable installation company to install your air source heat pump system. All HIES accredited installers undergo comprehensive checks during the application process and are continually monitored throughout their membership.
Questions to Ask
It’s worth thinking about your main motivation to install a new heating and hot water system.
You should ask yourself, and an installer, some key questions to be certain that an air source heat pump is the correct renewable energy solution for you.
- Do I have enough space? Air source heat pumps need sufficient room and good airflow to operate efficiently, ideally in a sunny location. They can be wall-mounted or placed on the ground.
- Is my home insulated enough? To work effectively, an air source heat pump requires a well-insulated, draught-proof property, as it operates most efficiently at lower temperatures than traditional boilers.
- Gas or electric? An air source heat pump system might not be the ideal choice for properties that utilise mains gas, but it could prove an excellent option if replacing an electricity or coal system.
- What heat emitter system should I choose? Underfloor heating or warm air systems are more efficient with air source heat pumps, as they require lower water temperatures than radiators.