necro81 writes: The U.S. National Renewable Energy Laboratory has announced that it has developed a new method for air conditioning that reduces energy use by 50-90%. The DEVap system cools air using evaporative cooling, which is not new, but combines the process with a liquid dessicant for pulling the water vapor out of the cooled air stream. The liquid dessicant, a very strong aqueous solution of lithium chloride or sodium chloride, is separated from the air stream by a permeable hydrophobic membrane. Heat is later used to evaporate water vapor back out — heat that can come from a variety of sources such as solar or natural gas. The dessicants are, compared to typical refrigerants like HCFCs, relatively safe for the environment.