The International Energy Agency expects the global stock of room air conditioners (RACs) to triple between today and 2050, with critical implications for energy use and greenhouse gas emissions. Because China produces approximately 70% of the world's RACs, it is in a unique position to lead a global transition to higher-efficiency RACs with substantially lower environmental impact. To date, however, Chinese policies have targeted relatively modest RAC efficiency increases. We recommend that China target production of RACs that use low global warming potential (GWP) refrigerants and are at least as efficient as the most efficient RACs produced today in China or on the global market. Specifically, we recommend that China set minimum energy performance standards for RACs at China annual performance factor (APF) 5.4 in 2025 and China APF 6.9 in 2030. This leadership would provide a longer-term policy signal to RAC manufacturers in China, enabling them to meet the efficiency targets cost-effectively by providing adequate time for investment planning. We project that full implementation of our recommended policy could result in global electricity consumption savings of 74 petawatt-hours, CO2 reductions of 49 billion metric tons, and bill savings of 6 trillion U.S. dollars (cumulative benefits 2020–2050). The policy is viable in China because of its provision of long-term certainty for manufacturers and their demonstrated ability to produce low-GWP RACs with the required efficiencies. Exploiting the parallel transition away from high-GWP refrigerants under the Kigali Amendment to the Montreal Protocol would provide manufacturing efficiencies and substantial savings opportunities.