Dual Duct

Published February 2000

An HVAC system in which both heated and cooled air are simultaneously supplied to the work area in separate ducts, and temperature control of the area is achieved by varying the mix of hot and cold air at a constant air volume. The system provides constant air circulation and localized temperature control. Two-duct installation means higher first costs, and energy inefficiencies occur when both hot and cold air are used to reach a room temperature that is equal to, or nearly equal to, the outside ambient temperature.