The Model Regulation Guidelines supplement the United for Efficiency (U4E) Air Conditioner Policy Guide, “Accelerating the Global Adoption of Energy-Efficient and Climate-Friendly Air Conditioners.”1 It is voluntary guidance for governments in developing and emerging economies that are considering a regulatory or legislative framework that requires new room air conditioners to be energy-efficient and to use refrigerants with a lower global warming potential (GWP) than typical legacy refrigerants, and to ban the importation of used products. It covers products commonly used in residential and light commercial applications. An accompanying Supporting Information Document includes the underlying rationale and methodologies.