US environmental regulators will let old air conditioners keep running, even with banned chemicals

US environmental regulators are proposing to relax some rules about hydrofluorocarbons, a class of potent greenhouse gases. This means equipment like residential air conditioners and heat pumps that were made before the ban can still be installed, even if they contain these chemicals.

The US committed to phasing down hydrofluorocarbons, which are thousands of times more potent than carbon dioxide, as part of an international agreement. This proposal carves out an exception for existing equipment, potentially slowing the transition away from these chemicals. It also signals that supply chain issues can lead to regulatory flexibility, even for climate-damaging substances.