Coaxial dryer ducts save energy and increase productivity. The coaxial duct systems provide outside make-up air directly to commercial tumblers. This is done primarily to eliminate negative air pressure within the building, reduce energy consumption, and improve tumbler performance. It is fabricated from galvanized steel. The inner exhaust duct section shall be fabricated from a minimum 20 gauge galvanized steel. The outer intake duct shall be fabricated from a minimum 18 gauge galvanized steel for all coaxial ducts systems. The system consists of two separate ducts, the inner exhaust duct shall terminate with a flange connection, for connecting to the exterior exhaust duct which will run to the lint collector. The outer intake duct which extends to the atmosphere approximately 3'0″ above the roof level.