The International Electrotechnical Commission (IEC) has approved an updated IEC 60335-2-40 standard that significantly raises the charge limits for flammable refrigerants (A2L and A3 classes) for residential air conditioners, dehumidifiers, and heat pumps.
This decision followed years of discussions and opened up new opportunities for using environmentally friendly natural refrigerants in homes.
Key changes in charge limits
Before the changes were adopted, the standard strictly limited the charge of highly competitive flammable gases (for example, propane) to a fixed cap of 150 grams. The new rules introduce flexible calculated limits that depend on the lower flammability limit (LFL) of a specific gas and the design features of the equipment:
For A3-class refrigerants (high flammability, for example, propane R290): The limit has been increased to 4.94 kg for standard split systems (depending on the room area), provided that strict safety measures are observed. In standard unventilated rooms, a wall-mounted split system can now be charged up to 988 grams (previously 150 g).
For A2L-class refrigerants (low flammability, for example, R32): Maximum charge volumes have increased several-fold. This makes it possible to build more powerful residential multi-split and VRF systems without the risk of exceeding a safe concentration in the event of a leak.
The International Electrotechnical Commission (IEC, in English — IEC) is a leading global non-profit organization that develops unified international standards for all electrical, electronic, and related technologies.
Put simply, it is the main global body that determines how any equipment that consumes or generates electricity must be designed, operate, and be safety-tested.
Key facts about the IEC:
📅 History: The organization was founded back in 1906. Its headquarters are currently located in Geneva (Switzerland).
🤝 Scale: More than 170 countries take part in its work. National technical committees from different countries (including the CIS countries, the EU, the US, and Asia) work together on common rules.
🌐 The “big three” of standards: The IEC works in close partnership with ISO (International Organization for Standardization) and ITU (International Telecommunication Union). Together, they form the global regulatory framework for worldwide industry and trade.