An increasing emphasis on energy saving and environmental conservation requires that air conditioners and heat pumps be highly efficient. To this end, several government initiatives have been undertaken. For example, the U.S. Environmental Protection Agency (EPA)'s Global Programs Division is responsible for the assessment of alternative refrigerant performance and enforcement of the Clean Air Act. Another prime example is the ENERGY STAR initiative, a program formulated by the EPA/Climate Protection Partnerships Division and the Department of Energy (DOE), which promotes products that offer energy efficiency gains and pollution reduction.