AIR DUCT

A tube or conduit for conveying air from one place to another.

Carry air conditioned air to all rooms. They are made of sheet metal usually. Two shapes of ducts commonly used for carrying air are round and square duct. The round duct is more efficient based on volume of air handled. That is, less duct material is needed to make a large enough duct to carry the necessary air. Round ducts create the least resistance to air flow. Ducts should be insulated everywhere to prevent air from escaping through seams, cracks and holes. Use caulking, soldering or cover with asbestos Insulating tape. Paper fiber ducts should not be used when ducts are embedded In concrete.