R32 looks set to become the new standard refrigerant for split-type air conditioning systems
The demands of the EU F-Gas regulation for lower-GWP refrigerants is driving air conditioning manufacturers away from the R410A that has been universally used in DX systems for many years and towards new alternatives.
There is consensus among many manufactures that the best alternative is R32, an HFC that offers many of the same characteristics as R410A (because it is in fact one of the constituent parts of the blend that makes up R410A), but with a third of R410A’s GWP - 675 compared to 2088.
Not only does R32 offer operators the ability to comply with F-Gas for the foreseeable future, particularly on smaller split systems– the F-Gas rules will ban refrigerants over 750 GWP in single split systems from 2025, where charge sizes are under 3kW – but it offers a clutch of other benefits too.
A number of major Air Conditioners manufacturers have now launched ranges of split systems running on the refrigerant and there is a strong sense that R32 will relatively quickly become the standard for air conditioning, taking over from R410A.
Manufacturers also point to the fact that already in Japan, where many OEMs are based, some four million R32 units are currently in use.
R32’s characteristics enables manufacturers to offer end users a number of benefits for their installations, such as extended pipe lengths – 25% longer than previously possible in some cases; increased ‘lift’ from outdoor unit to indoor; and 20% lower system refrigerant volumes than R410A, thanks to higher volumetric capacity.
The slightly increased pressure and density also contributes to overall improved system efficiency over R410A, as well as a 10% reduction in system electricity consumption compared to R22, another common refrigerant in older AC systems.
Further advantages of the new refrigerant include increased heating capacity at lower ambients; more simple recovery and re-use, thanks to its single-component state; and easier leak repair, due to the lack of glide.
Although R32 is rated as an A2L, or ‘mildly flammable’ – it is in practice very difficult to ignite in day-to-day use, experts say, although some precautions are required to prevent accidental build-up of refrigerant, particularly during charging of systems. Manufacturers recommend use of extract fans while charging, particularly if the outdoor unit is used in an enclosed area. The standard EN378 defines requirements for safe concentration levels of the refrigerants.
With that understood, handling of R32 is relatively straightforward – flare connections, pipework and pressure testing requirements remain the same - although because of the mild flammability, it should only be used in AC equipment that is designed specifically for it.
R32 also requires recovery equipment and vacuum pumps specifically designed for A2L refrigerants (ATEX rated), together with gauges, leak detectors and reclaim cylinders compatible for R32.
UK trade body FETA says:
“Provided the required assessments have been made beforehand, installation of an A2L system should be no more difficult than an A1 [non-flammable] system.”
Manufacturers agree, stating that for installers, it will be in many respects like working with R410A, since system and equipment designs are similar.
Given all the inherent advantages, some manufactures believe that although R32 is an HFC – which like all HFCs is intended ultimately to be phased out of use in Europe under the F-Gas Regulations – it is destined for a relatively long life, particularly within smaller Air Conditioner units. As one senior AC executive said:
“I don’t see it as being simply a short term transitional refrigerant, I can see it having a life of 10-15 years in smaller capacity DX equipment – there is nothing on the horizon that is better.”
For smaller equipment at least, R32 seems destined to become the refrigerant of choice.