IMPORTANT: For extended duct work runs, the cross section area of the duct can only be increased to an extent. Maximum proportional duct work runs cannot exceed twenty (20) feet more than the original limitations of twenty (20) feet with two (2) elbows. When the duct work approaches the maximum limits as noted in this manual, a professional heating venting air conditioning (HVAC) firm should be consulted for proper venting information.
ALL 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 duct 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 the weather, a 90° elbow bent downward should be installed where the exhaust exits the building. If the exhaust duct work 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 nearest obstruction.
IMPORTANT: DO NOT use screens, louvers, or caps on the outside of opening of exhaust duct work.
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 airflow and should be spaced at least
IMPORTANT: The
IMPORTANT: No more than three (3) dryers should be connected to one (1) main common duct.
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