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Low-GWP refrigerants for refrigeration and air-conditioning systems in Japan

The heatpumping technology sector once again needs to shift refrigerants. And once again it is for environmental reasons. But the introduction of other substances means that other types of challenges need to be met, and this time handling of flammable and combustible refrigerants is on the top of the agenda.

It all started back in 1974. Nature published an article by American researchers Rowland et al. on the ozone depletion phenomenon caused by specified chlorofluorocarbons and hydrochlorofluorocarbons (CFCs and HCFCs), which were then used as refrigerants. The use of these substances was later regulated under the Montreal Protocol of 1987 and they were mainly substituted by hydrofluorocarbons, HFCs. So far so good – the immediate threat against the ozone layer was gone. But these new substances – the HFCs such as R410A, R404A and R134a – have been shown to have a high global warming potential. Therefore, also these need to be phased out and replaced with less harmful substances.

Japan has been an early adopter of the international agreements and protocols addressing the refrigerant issue. Already in 1988, one year after the Montreal Protocol, they launched their Top Runner Program by enacting a law concerning the Promotion of Measuresto Address Global Warming. And to encourage the recovery and destruction of refrigerants, the Fluorocarbon Recovery and Destruction Act was enacted in2001. In response to the Paris Agreement of 2015, Japan adopted the Global Warming Counter measures Plan in May 2016. The Plan shows the way towards a 26 % reduction in greenhouse gases by 2030 compared to 2013, and sets a goal of an 80% reduction by 2050.

The next step, then, is to find refrigerants with low global warming potential (GWP). Unfortunately, these types of refrigerants present a new kind of challenge: they tend to have weaker chemical bonds between the atoms and are therefore more unstable. This results in flammability.

This safety risk can be handled for some applications, but for others more expertise and analysis are needed. For example, residential as well as small commercial air-conditioners have been converted to low-GWP R32. On the other hand, for machines that require large quantities of refrigerants, the use of a flammable low-GWP refrigerant may not be appropriate. In general, many applications will probably use either mildly flammable refrigerants that are slightly combustible, orcarbon dioxide refrigerants. Hydrocarbon refrigerants in the refrigeration and cold storage field will be desirable as next-generation options.

In Japan, the characteristics of flammable refrigerants have been clarified and risk assessments have been carried out, in order to enact safety standards. In addition, the High-Pressure Gas Safety Act­ – which regulates safety standards for refrigeration and air-conditioning systems –­ has been relaxed. International regulations such as ISO 5149, IEC 60336-2-40, and IEC 60336-2-89 have also been significantly revised.

Kenji Matsuda, Senior Manager, The Japan Refrigeration and Air Conditioning Industry Association

This text is shortened by HPC.
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