Even on the hottest days, supermarkets and fast-food restaurants can be chilling. The reason: Grocers and burger chains must over-air-condition to dehumidify the air to keep frost from building up in their freezers and wallpaper from peeling. Now, Edison Electric Institute (EEI), a Washington utility group, has found a new way to dehumidify that avoids the chill and saves 15% in energy costs.
The idea centers around heat-transfer devices called heat pipes. These sealed tubes contain a refrigerant and are divided in half by baffles. A pipe is placed in a store's air conditioner between the incoming and outgoing airstreams--condensing out moisture from incoming warm air and discharging the heat created into the stream of cold air leaving the unit.
Unlike other dehumidifiers, the pipe uses no extra energy and has no moving parts. Some half-dozen supermarkets have installed the devices. Burger King has tested the idea in a St. Petersburg (Fla.) store and plans to use it nationwide.