Jun 19, 2010

90 Percent More Efficient Air Conditioner

PopSci -
National Renewable Energy Laboratory has invented a new air conditioning system that uses 50 to 90 percent less energy than the best available units. The Desiccant-Enhanced eVaporative air conditioner -- DEVap -- combines membranes, evaporative cooling and liquid desiccants in a way that has never been done before.

NREL mechanical engineer Eric Kozubal, who co-invented the system, says the goal is to revolutionize cooling while removing millions of metric tons of carbon from the air. It cools and dries the air in one step. Evaporative cooling, blowing air across a wet surface to promote evaporation, has long been used in swamp coolers, as Technology Review notes. The DEVap takes it a step further, dividing air into two streams that are separated by a polymer membrane.

Water passes through one airstream, making it cooler and wetter. The cooler air cools the membrane, which cools the air on the other side, without making that side any more humid.
Another process dries the air, making the system effective even in humid locales -- a big step toward reducing refrigeration-based air conditioning, which is used in most of the country and is responsible for about 5 percent of the nation's energy consumption.
The process uses much less energy than a traditional air conditioner, and doesn't rely on any refrigerants, which produce chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFC). That also helps the environment, because a pound of CFC or HCFC in refrigerant-based A/Cs contributes as much to global warming as 2,000 pounds of carbon dioxide, NREL says. Read full at PopSci
Sources [NREL, Technology Review]