Safety Standards for Propane Heat Pumps Under Review

Safety Standards for Propane Heat Pumps Under Review

North America: A working group responsible for updating the UL/CSA 60335-2-40 safety standard is progressing with revisions that would allow higher refrigerant charge limits for flammable A3 refrigerants, including propane (R290), in residential HVAC applications across the United States, Canada and Mexico. The revised text is expected to be completed in 2027 and incorporated into the fifth edition of the standard in 2028. The proposed changes would increase the permitted propane charge for outdoor air-to-water monobloc heat pumps from the current 114 g limit to as much as 4.94 kg, aligning more closely with international standards already adopted in Europe. Parallel amendments are also being developed under the ASHRAE 15.2 residential refrigeration safety standard.

The proposed revisions are supported by ongoing safety research led by organisations including Oak Ridge National Laboratory and the Air-Conditioning, Heating, and Refrigeration Technology Institute. Industry representatives stated that updated safety standards are required before manufacturers can certify and market higher-charge propane-based HVAC systems in North America. The revised standards are intended to support the 2030 building code cycle and could also be adopted under the United States Environmental Protection Agency's Significant New Alternatives Policy (SNAP) programme. Industry participants have also called for wider involvement from manufacturers in the standards development process as North America prepares for reduced availability of HFC refrigerants under the AIM Act and the Kigali Amendment.

Source: Natural Refrigerants