Air source heat pumps use refrigerants to help them convert heat energy from the air outside and use this to provide heating to our homes. For the last few years, R32 refrigerant has been commonly used in heat pumps and as heat pump technology has evolved, the type of refrigerant used in some heat pumps is also changing. In this blog, we take a closer look at R290 refrigerant and its role in home heating.
Air source heat pumps are playing an important part in helping to decarbonise home heating, being a core pillar in the future of low carbon heating. Within every heat pump, there is refrigerant gas which has a key role in the operation of a heat pump, enabling the production of useful heat that can warm the rooms in your home and provide hot water to your taps (read more about how air source heat pumps work in our Education Area). A number of refrigerants are used in heat pumps, such as R32 refrigerant, and as with any refrigerant gas, these can have an impact on the environment, specifically on the ozone layer. Some refrigerant gases have less of an environmental impact than others and legislation has encouraged the move towards these more environmentally friendly refrigerants, such as R290.
In this blog, we explain more about what R290 refrigerant is, some of its benefits, its safety, and share a comparison between R32 refrigerant (used in the award-winning Aerona³ R32 heat pumps) and R290 refrigerant (which used in the new Aerona 290 heat pump range).
What is R290 used for?
R290 refrigerant gas (which is the technical name for this natural hydrocarbon) is better known at the gas Propane and it is already widely used, for example in air conditioning systems and refrigeration, with its use in low carbon air source heat pump systems increasing as well. A hydrocarbon, R290 is non-toxic, odourless and has excellent thermodynamic properties which means that it can efficiently absorb heat energy from the air (when in a gas state) and transfer this to the wider heating system (when it cools into a liquid state). In addition to being highly energy efficient, R290 is also more sustainable compared to other refrigerants.
Inside a heat pump, R290 refrigerant is used in exactly the same way as R32 refrigerant with the refrigerant entering a cycle of changing from a liquid to a gas and back to a liquid. In the evaporator, where the air is drawn into the heat pump, the R290 refrigerant is exposed to the air where the refrigerant boils off to a gas and absorbs the latent heat energy from the air. As a gas, the R290 refrigerant is them compressed (in the heat pump’s compressor) where the heat content is increased further before the gas passes through the heat exchanger. At this point, the R290 gas condenses back to a liquid and it transfers its heat to the water in the heating system before re-circulating and repeating this cycle.
What are the benefits of using a R290 heat pump?
As well as being a more environmentally friendly refrigerant, R290 offers a range of other benefits to heat pumps including excellent efficiencies and low noise levels. We have outlined some of these benefits below but for a more in-depth look at the advantages of R290 heat pumps, please visit our Knowledge Hub.
Good for the environment
Every refrigerant gas has a GWP value calculated. GWP stands for Global Warming Potential which represents the amount of time a gas remains active in the atmosphere and its impact on warming the atmosphere during this time. For example, R410a refrigerant, which was used in heat pumps several years ago, had a GWP of 2088. Meanwhile, R32 refrigerant has a GWP of 675. R290 refrigerant, which is a natural refrigerant, has a very low GWP of just 3 so it is deemed to be more environmentally friendly than other refrigerants and this is one of the reasons why its use in heat pumps will be increasing.
Regulations set out by the European Union and adopted by the UK Government are striving to reduce the use of F-gases (fluorinated greenhouse gasses), which are human-made, in favour of natural gases, such as R290. The use of R290 refrigerant in heat pumps, such as Grant’s new Aerona 290 air-to-water heat pump, will therefore further help this low carbon heating technology to be even more environmentally friendly by using a refrigerant that has an incredibly low GWP.
Efficiency
As mentioned earlier, R290 has excellent thermodynamic properties which enables it to capture heat energy and release it again in a very effective way within a heat pump, which in turn makes the system itself very efficient. As a result, the Grant Aerona 290 achieves an A+++ ErP energy rating at 35°C flow temperature.
Noise levels
The acoustics of a heat pump are incredibly important because air source heat pumps are located outdoors and they therefore must not be a nuisance either to the household occupants or neighbouring properties. This is why Grant’s Aerona 290 heat pump has been designed to operate with ultra-low noise levels.
Is R290 refrigerant safe?
R290 refrigerant is more flammable when compared to F-gases so, as with any gas, it must be safely handled and only by those suitably trained. The design of the heat pump in which R290 is used is also crucial to support safe use of this gas. Such safety design features include larger casings to house the R290 refrigerant in both gas and liquid form, specially designed compressors which have minimal vibration and anti-leak features, and safety enhanced components such as an R290 leak sensor located within the casing itself, spark free sealed relays and ceramic fuses. R290 heat pumps also require larger clearances around them when being installed.
This is why it is important that a trained heat pump professional should carry out the installation. If you are interested in having a heat pump fitted at your home and you want to discuss the options available to you, please use our Find an Installer search to find local heat pump installers in your area.
R32 vs R290 – a comparative look
As mentioned above, one of the main differences between R290 refrigerant and R32 refrigerant is their GWP values – the GWP of R290 is 3 and the GWP of R32 is 675. R32 is a type of F-gas and R290 is a type of natural refrigerant. While R290 is more flammable than R32, both refrigerants have low toxicity levels. Both are energy efficient but R290 refrigerant is considered to be more efficient. R290 refrigerant evaporates at a slightly higher temperature compared to R32 and it has a lower condensing temperature as well.
The infographic below provides a comparison of the main differences between R32 refrigerant and R290 refrigerant.
Grant UK, suppliers of air source heat pumps
Grant UK have been supplying air source heat pumps since 2010 with the new Aerona 290 range being their fifth generation of heat pumps. Launched in the Autumn 2024, the Aerona 290 is an eye-catching heat pump which combines sleek aesthetics, quality design and the use of R290 refrigerant. To receive further information about this exciting new product, please subscribe to the Grant UK mailing list.