IMPORTANT: For extended duct work runs, the cross section area of the duct work can only be increased to an extent. Maximum proportional duct work runs cannot exceed fifteen
(15)feet with two (2) elbows. When the duct work approaches the maximum limits as noted in this manual, a professional HVAC firm should be consulted for proper venting. HVAC should be consulted for proper venting information.
IMPORTANT: Exhaust back pressure measured by a manometer at each dryer exhaust duct area should not exceed .3 inches of water column (W.C.).
The duct work should be smooth inside with no projections from sheet metal screws or other obstructions which will collect lint. When adding ducts, the duct to be added should overlap the duct to which it is to be connected. ALL duct work joints must be taped to prevent moisture and lint from escaping into the building. Inspection doors should be installed at strategic points in the exhaust duct work for periodic inspection and
NOTE: Where the exhaust passes through a wall, ceiling, or roof made of combustible materials, the opening must be
a.Outside Duct Work Protection
1)To protect the outside end of horizontal duct work from whether, a 90º elbow bent downward should be installed where the exhaust exits the building. If the duct work travels vertically up through the roof, it should be protected from the whether by using a 180º 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 or caps on the outside of opening of exhaust duct work.
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