16
It is important that the duct work from each dryer not exceed fifteen (15) feet with no more than (2) elbows
(excluding dryer connections and outside exhaust outlets). If the duct work exceeds fifteen (15) feet or has
numerous elbows, the cross section area of the duct work
must be
increased in proportion to the length and
number of elbows in it. In calculating duct size, the cross section area of a square or rectangular duct
must be
increased by twenty (20) percent for each additional fifteen (15) feet. The diameter of a round exhaust duct
should be increased ten (10) percent for each additional fifteen (15) feet. Each 90º elbow is equivalent to an
additional thirty (30) feet, and each 45º elbow is equivalent to an additional fifteen (15) feet.
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 more than the original limitations of the maximum limit 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
clean-out of lint from the duct work.