The maximum allowable charge amount for R290 per refrigerant circuit has increased to 494g, following the IEC standard for plug-in commercial cases.
Japan’s adoption of a higher charge limit for hydrocarbon refrigerants in plug-in commercial refrigeration cases is expected to encourage further uptake of hydrocarbons in Japan's food retail sector in the next few years, regional stakeholders say.
The charge limit increase took place in March, when the Japanese Industrial Standards Committee (JISC), Japan's national standardization body, published Japanese Industrial Standard (JIS) C9335-2-89:2021. It aligns with the global standard, IEC 60335-2-89:2019,
These standards updated the maximum allowable charge amount of flammable refrigerants to be used in stand-alone plug-in commercial refrigeration and freezing cases.
According to the update, the maximum allowable charge amount for propane (R290), per refrigerant circuit, increased to 494g (1.09 lbs), or 13 times the lower flammability limit (LFL) value for R290, which is 0.038 kg/m3. The LFL value of isobutane (R600a), 0.043 kg/m3, gives it a maximum allowable charge amount of 559g (1.23 lbs), per refrigerant circuit.
The previous version of the standard, JIS C9335-2-89:2005, limited the charge amount of flammable refrigerants to 150g (0.33 lbs).
Notably, the clause in the IEC standard that specifies a maximum charge limit of 1,200g (2.65 lbs) for A2 and A2L refrigerants has been removed in the JIS text.
Some experts believe that this has left the door open for HFC and HFO refrigerants to be used in larger amounts and in wider applications. R32, for example, has a specified LFL of 0.307 kg/m3, which means up to 3,991g (8.8 lbs) of R32 will be allowed in a single refrigeration circuit.
Lengthy risk assessment
The publication of this standard follows a lengthy risk assessment process conducted by the Japan Refrigeration and Air Conditioning Industry Association (JRAIA), which has spanned the past several years.
JRAIA has subsequently published two additional safety standards and guidelines (JRA 4078:2021 and JRA GL-21:2021), which are based on the new JIS standard and provide additional details for Japan's manufacturers, installers and technicians working with hydrocarbons.
Japan's major commercial refrigeration equipment manufacturers have already taken significant steps in the past few years towards expanding the use of hydrocarbons in their product lineups.
In June, Japanese OEM Daikin announced that it will begin sales of R290 plug-in showcases, under the Daikin brand and manufactured by its European subsidiary AHT, for the Japanese market.