No change to hydrocarbon charge limit announced
Recent news that the International Electrotechnical Commission (IEC) voted against increasing the allowable charge for A3 flammable refrigerants (hydrocarbons) from 150 g to approximately 500 g under the IEC 60335-2-89 standard was a blow for many manufacturers of small commercial cabinets. The vote, which had previously looked likely to be passed, was rejected by 1 vote from the observing and participating national committees. Although the vote may be reviewed it is unlikely that this will happen in the near future.
The failure of the vote also has impacts for A2 and A2L low flammability gasses. It has been reported that a key point in the vote was the proposal that would have allowed A2L refrigerant charges to increase from 150 g to 1.2 kg. This could have a critical impact on the uptake of these refrigerants.
Hydrocarbons have ultra-low global warming potential and are considered to be ‘natural’ refrigerants. They are classified as A3 refrigerants (flammable) and so need to be managed to ensure they are safe. Most manufacturers of small commercial systems wish to produce cabinets that can be installed without any restriction in the size of the room where the cabinet is located and so will need to comply with the 150 g refrigerant charge restriction (otherwise higher refrigerant charges can be applied under EN378 where room size/zone restrictions would be applied). Producing small to medium sized commercial cabinets operating on a hydrocarbon charge of less than 150 g is challenging. Hydrocarbons do, however, have excellent thermal properties and so it seems technically more feasible to operate small commercial cabinets using hydrocarbons than to operate these types of cabinets using an A2L refrigerant (which will have the same 150 g charge limit). With careful design, refrigerant charge can be minimised and this can be done through optimisation of the system performance or applying components that enable refrigerant charge to be reduced.
Please do contact us if you would like to know more about optimisation or safety assessment of refrigerated cabinets operating on hydrocarbons. For more information contact Alan Foster at RD&T (alan.foster@rdandt.co.uk).