Mark Vender
Charge sizes for flammable refrigerants in HVAC&R equipment are changing with a proposal to raise international limits for room air conditioners, and the adoption of a new standard in Australia for refrigeration appliances.
An International Electrotechnical Commission (IEC) working group has released a proposal to update safety standard IEC 60335-2-40. This would allow larger amounts of flammable refrigerants such as propane (R290) and R32 in split system air conditioners, heat pumps and dehumidifiers.
In the case of hydrocarbons, the change would not increase charge sizes for appliances used in very large rooms; this would remain at about 1kg. But it would change the charge for an ordinary-sized room. To hold this increased charge, systems will need circulation airflow, safety shut-off valves, and will need to satisfy new construction requirements for a more robust design.
At the moment, the international standard allows a split system in a 20m2 room with 2.2m ceilings to contain 334g of A3 refrigerant such as R290. Under the new standard, and with the above safety measures in place, the same system could hold up to 988g of R290.
For A2L refrigerants, such as the commonly used R32, charge sizes would also increase significantly. As noted in The Cooling Post, for an R32 system with a robust design serving three rooms with ceiling-mounted units, each room being 15m2 with a ceiling height of 2.2m, the current standard allows 2.5kg of R32 if no additional safety measures are applied. With the new proposal this limit will be 7.5kg.
The Environmental Investigation Agency (EIA), which recently called for a move from HFCs to hydrocarbons in all split systems, has backed the proposed standard.
“Climate-friendly hydrocarbon refrigerants have been safely used in billions of household refrigerators around the world for decades, but have been largely blocked in air conditioning by outdated standards,” says Christina Starr, Senior Climate Policy Analyst with EIA US and a member of the US standards technical panel for UL 60335-2-40.
“It is incredibly important for countries to support this proposal to unlock the full climate benefits of reducing HFCs and increasing energy efficiency in cooling.”
Member countries represented on the IEC’s sub-committee 61D have until October 30 to vote on the proposal. If passed, the new standard could be published by the end of 2021, and would then need to be adopted by regional and national standards bodies.
Meanwhile, in Australia and New Zealand, the increased charge size for flammable refrigerants approved by the IEC last year has now been adopted locally.
AS/NZS 60335.2.89:2020 is an identical adoption of IEC 60335-2-89, which lifts the maximum allowable charge of flammable refrigerants in appliances such as refrigerated display and storage cabinets, refrigerated trolley cabinets, service counters and self-service counters, blast chillers and blast freezers, and commercial ice-makers.
For A3 refrigerants such as hydrocarbons, the maximum charge size has increased from 150g to about 500g. For A2L refrigerants, it has increased from 150g to 1,200g.
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