Enabling Ultra-low GWP Cooling and Heating: Updating U.S. Safety Standards and Codes

As manufacturers develop next generation cooling and heating technologies to meet growing global needs, it is critical to open up the US market to ultra-low GWP refrigerant options for the residential and commercial air conditioning and heat pump sector.

Hydrocarbon refrigerants, such as propane (R-290) are efficient, cost-effective, and gaining traction in global markets as alternatives to hydrofluorocarbons (HFCs). Timely action to update US standards and codes to align with international best practice for safe design and installation of new equipment using hydrocarbons can support a smooth transition to highly efficient, and highly sustainable near-zero emissions cooling and heating. Without such action, the U.S. risks losing ground in global markets and locking in less sustainable and more costly alternatives.

Our report outlines feasible paths for US safety standards and building codes for refrigerants – primarily UL 60335-2-40 and ASHRAE 15 – to align with IEC 60335-2-40. Technical analysis concludes that full harmonization of U.S. standards with IEC, could enable 78–88% of new US AC/HP equipment sales to transition to hydrocarbons between 2030 to 2035 – cutting emissions while keeping U.S. manufacturers globally competitive. The recommendations are practical, urgent, and consistent with international progress already underway.