(2010-09-20) Super Efficient Air Conditioning

NREL has developed an innovative Air Conditioning concept that promises to cut electrical demand by up to 90 percent — and it works well in both Gulf Coast humidity and desert heat... Swamp coolers work well when the outside air is dry, as evaporating water carries away heat, cooling and moistening the air that is re-circulated into the house... He says that in Phoenix, where the annual monsoon and human activities like irrigation raise summertime humidity levels, there might be as many as six weeks each year where evaporative cooling won’t work... In building a prototype, the NREL researchers used a calcium chloride salt solution as a desiccant and relied on a technical breakthrough from a company that had found a way to keep tiny, corrosive desiccant droplets from leaking into the metal ductwork of the device... In modeling how the D E Vap system would perform in Phoenix, “we get on the order of 90 percent savings” in electrical demand, Judkoff says, when compared with a high-efficiency 18 SEER vapor compression air conditioner. The system sees a 50 percent power savings even in swampy Houston-like conditions, Judkoff says. While others have proposed somehow combining evaporative and desiccant cooling, Judkoff says NREL is the first to come up with a practical, cost-effective approach.