Air Source Heat Pumps

How to choose the right air source heat pump for your home

A 17kW heat pump installation

Making the move to renewable home heating is a sustainable life choice that more and more homeowners are choosing with the number of air source heat pump installations increasing every year. In this article, we talk through the key stages that homeowners should follow to ensure they find the right heat pump for their home.

Low carbon heating systems will play a pivotal role in helping the UK to work towards Net Zero carbon targets. Air source heat pumps have seen their popularity significantly grow in recent years and this trend will continue as more households transition from fossil fuel heating systems to more environmentally friendly solutions. Heat pumps are not a new technology but, as with every heating system, if they are installed incorrectly, this can cause problems later down the line. It is therefore important that homeowners and their installers get it right first time round so here we will explain the main steps that should be completed when planning and completing an air source heat pump installation including system design, heat pump sizing, efficiency as well as finding the right heat pump installer.

How do air source heat pumps work?

Air source heat pumps are available as either air-to-air heat pumps (which extract heat from the air outside and transfer this heat into the air inside a home) or air-to-water heat pumps (which extract heat energy from the air outside and transfer this into the water which is then circulated through a heating and hot water system within the property, for example through radiators or underfloor heating, to then warm up rooms within the home). Grant air source heat pumps are air-to-water heat pumps which are incredibly energy efficient, effectively transferring heat energy from the natural environment outdoors and utilising this energy within the home. Please refer to our Education Area to read more about how air source heat pumps heat homes.

Heat Pump Installation and Sizing

To ensure that a heat pump system achieves its maximum efficiencies, it is incredibly important that the heat pump is correctly sized. If too small a heat pump is installed, it will be unable to meet the heating requirements of a property and if too large a heat pump is fitted, the system may not be as efficient. This is why a thorough assessment of your home’s efficiency should be the first thing your installer completes – by carrying out a room by room heat loss calculation of your property, the heating demand of your home can be confirmed which considers your room sizes, the build type of the property, the level of heat loss from your windows, doors, walls and roof areas and determine if any of these could be upgraded to improve the efficiency of the property, as well factoring in your personal preferences regarding room temperatures. Once your heating demand is confirmed, the right heat pump model with the appropriate output can be selected.

During this planning stage, your installer can also discuss with you the suitable location to site your heat pump. Heat pumps need sufficient clearances around them to ensure that there is an unobstructed airflow. It is also important to factor in nearby windows and the proximity of the heat pump to neighbouring boundaries and properties. Please visit our blog to read more about heat pumps and planning permission. As some of our case studies demonstrate, Grant heat pumps can be fitted in an array of different types of properties and locations, from large new build homes through to hard to heat properties, as well as barn conversions and heating system upgrades.

Consider energy efficiency and electrical consumption

A common term you may notice when researching heat pumps is ‘SCOP’ which stands for Seasonal Coefficient of Performance and it is a measure of heat pump efficiency. In brief, the SCOP value is produced by calculating a heat pump’s overall performance during a particular heating season (warm, average or cold) and dividing this by the annual energy consumed by the heat pump during operation. The Grant Aerona³ 6kW output heat pump, for example, produces 6kW at a SCOP of 4.61 at a low temperature and in average climate conditions – what this means is that for every kilowatt of energy used to run the heat pump, over 4kW of energy is being given to the heating system. The higher the SCOP, the more efficient the heat pump so it is an important consideration when choosing an air source heat pump.

Grant’s Aerona³ R32 air source heat pump range comprises of four models with outputs ranging from 6kW up to 17kW.

6kW Air Source Heat Pump

  • Ideally suited for smaller homes
  • Compact size and footprint
  • SCOP of 4.61 (BS EN 14825 average climate conditions at 35° flow)
  • A+++ ErP rating

10kW Air Source Heat Pump

  • Ideally suited to medium-sized homes
  • Compact design and footprint
  • SCOP of 5.20 (BS EN 14825 average climate conditions at 35° flow)
  • A+++ ErP rating

13kW Air Source Heat Pump

  • Ideally suited to larger homes with greater heating demands
  • Awarded the Quiet Mark
  • SCOP of 5.40 (BS EN 14825 average climate conditions at 35° flow)
  • A+++ ErP rating

17kW Air Source Heat Pump

  • Ideally suited to properties with substantial heating requirements, making it suitable for large homes and some commercial applications as well
  • Awarded the Quiet Mark
  • SCOP of 4.54 (BS EN 14825 average climate conditions at 35° flow)
  • A+++ ErP rating

Discover more about Grant’s range of air source heat pumps.

Look for a local air source heat pump installer

When you are ready to take the next step and get a quotation for a new heat pump heating system for your home, you will need to find a local heat pump installer in your area. When looking for a competent air source heat pump installer, it is worth checking their credentials – for example, have they completed manufacturer product training and are they a member of a competent persons scheme – as well as looking at their customer reviews and testimonials. The G1 Installer Scheme is Grant UK’s installer network and installers who have completed the Aerona³ Heat Pump Product Training Course are eligible to offer 7 year guarantees on their Aerona³ installations (terms and conditions apply). To find local G1 heat pump installers in your area, please visit our Find an Installer online search.

What to expect with the heat pump installation process

Every heat pump installation is different but whether you are opting for a 6kW, 10kW, 13kW or 17kW heat pump, the heat pump installation process will follow a similar set of steps which we have outlined below – it is important that when installing a Grant heat pump, the engineer installs the heat pump in accordance with Aerona³ Installation Manual.

  1. Site Assessment – as outlined above, a heat loss calculation should be carried out by your installer to ascertain the heat loss of your property and its space heating requirements. A thorough site survey should also be undertaken by your installer to determine the location for siting the heat pump, electrical supply and connections, and other factors which will influence the wider system design.
  2. Sizing – based on the site survey and heat loss calculation, your installer will be able to specify the correct air source heat pump size you will need for your heating requirements. This could be a 6kW, 10kW, 13kW or 17kW output heat pump from Grant UK. Your installer will also specify other products and components needed to complete your heat pump system installation, such as a hot water cylinder.
  3. Electrical requirements – during the planning phase, your installer will need to check the electrical supply to your property and ensure it can accommodate the additional requirements that a heat pump will demand. If the chosen heat pump model is not Connect and Notified approved, your installer will need to inform the local Distribution Network Operator (DNO) prior to installation. For heat pump models which are Connect and Notified approved, such as the 10kW, 13kW and 17kW Aerona³ outputs, the DNO notification can be completed retrospectively, within 28 days of the installation being completed.
  4. Installation – once you have approved your installer’s quotation and the necessary pre-installation steps have been completed, your heat pump’s installation process can begin. The site where the heat pump will be fitted will need to be prepared as this must be a solid base before the heat pump can be moved into position and the relevant system connections made.
  5. Piping and wiring – as part of the installation, your installer will need to ensure that all pipework is correctly insulated to prevent heat loss and to prevent damage due to frozen pipes. The electrical connections will also need to be completed – this will either be completed by your engineer or by a separate electrician.
  6. Commissioning – once the heat pump and system components are fully set up, your installer can then commission the system. This will involve finalising the settings for your system, ensuring the controls and parameters are correctly set up to help your heat pump to operate efficiently. During this stage, your installer will test the system to make sure the heat pump is functioning correctly.
  7. Customer handover – your installing engineer should carry out a comprehensive handover to ensure you understand how your new system will work. Grant UK supply a handy handover guide with each of their Aerona³ heat pumps and a series of supporting video tutorials are also available on Grant UK’s YouTube channel here.

How Grant can help you

Grant air source heat pumps are an award-winning range of heat pumps with the Aerona³ range announced as Heat Pump Product of the Year (National ACR & Heat Pumps 2022). The range is not only incredibly efficient with excellent SCOPs but each heat pump is quiet in operation, has compact footprints and design and they have minimal impact on their local surrounds. Please view Grant’s heat pump range here or alternatively you can contact our team.

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