112144 - 46
www.adclaundry.com
19
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 45º in the direction of airflow. The main duct
should be
tapered, with the diameter
increasing before each individual 10-inch (25.4 cm) duct (when dryer common exhaust is used) is added. If
single 6-inch (15.24 cm) basket (tumbler) exhaust ducts are used, the diameter
should be
increased after every
second 6-inch (15.24 cm) duct.
IMPORTANT:
No more than four (4) dryers or eight (8) baskets (tumblers) total
should be
connected
to one (1) main common duct.
NOTE:
for examples of multiple dryer (common) venting.
The main duct may be any shape or cross-sectional area so long as the minimum cross-sectional area is provided.
The
show the minimum cross-sectional area for multiple dryer venting. These figures
must be
increased in proportion if the main duct run from the last dryer to where it exhausts to the outdoors is
unusually long (over 15 feet [4.57 meters]) or has numerous elbows (more than one [1]) in it. In calculating
ductwork size, the cross-sectional area of a square or rectangular duct
must be
increased twenty percent (20%)
for each additional 15 feet (4.57 meters). The diameter of a round exhaust
must be
increased ten percent (10%)
for each additional 15 feet (4.57 meters).
IMPORTANT:
For extended ductwork runs, the cross-sectional area of the ductwork can only be
increased to an extent. Maximum proportional ductwork run
cannot
exceed 15 feet
(4.57 meters) more than the original limitations of 15 feet (4.57 meters) with two (2)
elbows. When the ductwork approaches the maximum limits as noted in this manual,
a professional heating, venting, and air conditioning (HVAC) firm
should be
consulted for proper venting information.
IMPORTANT:
Exhaust back pressure measured by a manometer at each basket (tumbler) exhaust
duct area
must be
no less than 0 and
must not exceed
0.3 inches (0.74 mb) water
column (W.C.).
The ductwork
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
ductwork joints
must be
taped to prevent moisture and lint from escaping into the building.
Also, inspection doors
should be
installed at strategic points in the exhaust ductwork for periodic inspection
and cleaning.
NOTE:
When the exhaust ductwork passes through a wall, ceiling, or roof made of combustible
materials, the opening
must be
2-inches (5.08 cm) larger than the duct (all the way around).
The duct
must be
centered within this opening.
Summary of Contents for AD-320
Page 20: ...16 American Dryer Corp 112144 46 ...
Page 21: ...112144 46 www adclaundry com 17 ...
Page 22: ...18 American Dryer Corp 112144 46 ...
