Comparing air source heat pump outputs

Air source heat pumps are a low carbon heating system which cleverly utilise the low-grade heat energy in the air outside and convert this into energy that can be used to heat homes and their hot water. Just like traditional boilers, heat pumps come in different heating outputs – for example, the Grant Aerona³ R32 air source heat pump range comprises of four models including a 6kW output heat pump, 10kW heat pump, 13kW heat pump and 17kW heat pump.

When it comes to choosing the right size of heat pump, it is important that a thorough assessment of your property’s build type, size and location is carried out, along with an accurate room by room heat loss calculation. In addition, the space heating and hot water requirements and hot water of the household must also be factored in. Your installer will combine the results of the site survey and heat loss calculation of your home and, from the results, specify the correct size of heat pump that will be able to meet the heating and hot water requirements of your home. Please read on to learn more about the different air source heat pump outputs, their typical installation scenarios and also what you should be looking for in an air source heat pump.

Why are air source heat pump outputs important?

The output of a heat pump denotes how much energy it can contribute to a heating system. It is crucial that the correct heat pump output is selected in order to meet the heating demand of your property. If the heat pump fitted is undersized, it will not produce sufficient heat output to fulfil the requirements of your home. If the heat pump fitted is oversized, it is likely that the system will not be as efficient as one that has been correctly sized and designed. Once a thorough heat loss calculation has been carried out, your installer will be able to confirm the heating demand of your home and select and install a heat pump model that can meet that demand.

When researching the right heat pump for your home, visit our guide here which answers ten questions homeowners should ask before buying a heat pump.

What is a kW?

kW stands for kilowatt, which is a unit of energy, and with air source heat pumps, it refers to the maximum amount of energy the unit can produce under certain conditions. It is important to note that this maximum kW figure does not equate to the actual amount of energy a heat pump will contribute to a heating system – there are a variety of factors that will determine how much energy a heat pump can give to a heating system, such as the efficiency of the building being heated, the outside air temperatures and the flow temperatures that are required to heat the emitters in the property.

What are the different types of air source heat pump outputs?

There are a range of different air source heat pump outputs available including smaller, single fan units (such as the Aerona³ R32 6kW heat pump and 10kW heat pump) as well as larger heat pump models which have a twin fan (including Grant’s Aerona³ R32 13kW air source heat pump and 17kW heat pump). You can visit our Knowledge Hub to learn more about the differences in these heat pump outputs.

6kW Air Source Heat Pump

The Aerona³ 6kW ASHP is a small unit with an incredibly compact footprint and, as showcased in one of our case studies, it can be ideally suited to homes which have a low heat loss, low space heating and hot water demand.

Read our case study here which follows the installation of six Aerona³ 6kW heat pumps at a sustainable development of flats and houses in Cornwall.

10kW Air Source Heat Pump

The Aerona³ 10kW also has a compact footprint and can fulfil the heating requirements for medium-sized properties or properties where the insulation levels are adequate but not as well insulated as a new build for example. The Grant Aerona³ 10kW heat pump has been installed in multiple installation scenarios as demonstrated in our case studies below.

Read more about how an Aerona³ 10kW heat pump upgraded the heating system of a sixteen year old farmhouse and learn about the installation of an Aerona³ 10kW heat pump at a 4-bedroom new build home.

13kW Air Source Heat Pump

The Aerona³ 13kW heat pump model is well suited to larger properties or households which have a larger demand for space heating and hot water. Please visit The Grant House in our Knowledge Hub to discover how an Aerona³ 13kW heat pump helped a Wiltshire family home transition from a gas central heating system to renewables.

17kW Air Source Heat Pump

The fourth heat pump output available in the Aerona³ R32 range is the 17kW model which is typically installed in large homes or small commercial buildings. It is well suited to properties which have a higher heating and hot water demand and, as shown in these case studies, can be fitted in new builds and retrofit installations.

Learn more about the installation of an Aerona³ 17kW heat pump in a hard-to-heat bungalow , click here to read about a 17kW heat pump installed a large 4-bedroom home or the installation of a 17kW heat pump at new build farmhouse.

What factors should be considered when choosing an air source heat pump output?

There are multiple factors which will influence the size of heat pump your home needs and we have outlined some of these below:

- Building size – the size of your home, including the footprint of your rooms and the height of your ceilings, is an important starting point. Larger spaces will need more energy to be kept warm so a heat pump with a larger output will likely be required.

- Insulation – how much insulation your home has (in the walls, roof, doors and windows) will determine the amount heat that is escaping from the property. Buildings with higher heat losses will need larger heat pumps whereas well insulated properties are more energy-efficient and may, therefore, require a smaller sized heat pump.

- Climate – the average local weather conditions should also be considered when calculating the heat loss of a property. Extremely low temperatures can reduce the output and efficiency of a heat pump although it is important to highlight that heat pump can operate in temperatures below freezing – read our heat pump myths article to learn more. Homes which are located in areas with extreme temperatures or which are exposed may need a higher heat pump output model.

How to calculate the right size air source heat pump for your home

If you are thinking about installing a heat pump in your home, a good place to start is with your research. Use online resources, such as our Knowledge Hub, to learn more about how air source heat pumps work and how heat pump systems operate differently to a conventional boiler. You should then research the models available, their features and benefits, and contact local heat pump installers in your area.

Grant UK - suppliers of air source heat pumps

Here at Grant UK, we have in-house renewables experts who can help heating installers and their customers specify the correct heat pump heating system. Alongside the supply of our highly efficient air source heat pumps and package solutions , Grant UK are also on hand to answer queries and support customers as they transition to low carbon heating. Contact a member of our Team here.