NOTE: When the exhaust ductwork passes through a wall, ceiling, or roof made of combustible materials, the opening must be
a.Outside Ductwork Protection
1)To protect the outside end of the horizontal ductwork from the weather, a 90° elbow bent downward should be installed where the exhaust exits the building. If the ductwork travels vertically up through the roof, it should be protected from the weather by using a 180° turn to point the opening downward. In either case, allow at least twice the diameter of the duct between the duct opening and the nearest obstruction.
IMPORTANT: DO NOT use screens, louvers, or caps on the outside opening of the exhaust ductwork.
3.Multiple Dryer (Common) Venting
If it is not feasible to provide separate exhaust ducts for each dryer, ducts from individual dryers may be channeled into a “common main duct.” The individual ducts should enter the bottom or side of the main duct at an angle not more than 45° in the direction of the flow and should be spaced at least
IMPORTANT: The dryer is not provided with a back draft damper. When exhausted into a multiple (common) exhaust line, a back draft damper must be installed at each dryer duct.
IMPORTANT: No more than three (3) dryers should be connected to one (1) main common duct.
The main duct may be any shape or
1.These figures must be increased in proportion if the main duct run to the last dryer to where it exhausts to the outdoors is unusually long (over 20 feet [6.09 meters]) or has numerous elbows (more than two [2]) in it. In calculating ductwork size, the
IMPORTANT: For extended ductwork runs, the cross section area of the ductwork can only be increased to an extent. Maximum proportional ductwork runs cannot exceed 20 feet (6.09 meters) more than the original limitations of 20 feet (6.09 meters) with two (2) elbows. When the ductwork approaches the maximum limits as noted in this manual, a professional heating, ventilating, and
IMPORTANT: Exhaust back pressure measured by a manometer in the exhaust duct must be no less than 0 and must not exceed 0.3 inches (0.74 mb) of water column (W.C.).
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