B&C Technologies DP-250 Industrial - Manual (Page 20)

INSTALLATION PROCEDURES
3-6
Figure.3-4 Single Dryer Venting
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
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 (HV AC) 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 clean-out of lint from the duct work.
NOTE: Where the exhaust duct passes through a wall, ceiling, or roof made of combustible
materials, the opening must be 2-inches larger (all the way around) than the duct. The duct
must be centered within this opening.
Outside Duct Work Protection
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.