The demand for air conditioning in homes and work spaces is increasing. New and more efficient cooling methods are needed to reduce building energy consumption and environmental impact. Residential and commercial buildings currently account for 72% of the nation's electricity use and 40% of our CO₂ emissions each year, 5% of which comes directly from space cooling and/or air conditioning. In addition, the refrigerants used in air conditioners and space cooling are potent greenhouse gases (GHGs) that may contribute to global climate change. These refrigerants can trap 1,000 times more heat in the atmosphere than CO₂ alone. Because the overwhelming majority of air conditioning and cooling systems run on electricity, and most U.S. electricity comes from coal-fired power plants which produce CO₂, there is a pressing need to support improvements that increase the efficiency of these technologies and reduce the use of GHG refrigerants in the decades to come.