ADC ES35/35, Installation & Operator'S Manual, Page: 10 / 24

10 American Dryer Corp. WFR 112807 - 15
NOTE 1 Opening from combustible materials must be 2-inches (5.08 cm)
larger than the duct (all the way around). The duct must be centered
within this opening.
NOTE 2 Distance should be 2 times the diameter of the duct to the nearest
obstruction.
A = 8-inches (20.32 cm)
B = 12 feet (3.66 meters)
NUMBER OF DRYERS 4 3 2 1
MINIMUM CROSS-
SECTIONAL AREA
SQ IN 164 120 80 54
SQ CM 1058 774.2 516.1 348.4
MINIMUM ROUND
DUCT DIAMETER
IN 14 12 10 8
CM 35.56 30.48 25.4 20.32
Outside Ductwork Protection
To protect the outside end of the horizontal ductwork from
the weather, a 90° elbow bent downward should be installed
where the exhaust exits the building. If the ductwork 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 the nearest obstruction (refer
to the diagram).
IMPORTANT: Do not use screens, louvers, or caps on the
outside opening of the exhaust ductwork.
Single Dryer Venting
IMPORTANT: For extended ductwork runs, the cross-
sectional area of the ductwork can only be increased to an
extent. When the ductwork approaches the maximum
limits as noted in this manual, a professional HVAC firm
should be consulted for proper venting information.
NOTE 1 Opening from combustible materials must be 2-inches (5.08 cm)
larger than the duct (all the way around). The duct must be centered
within this opening.
NOTE 2 Distance should be 2 times the diameter of the duct to the nearest
obstruction.
A = 12 feet (3.66 meters)
B = 8-inches (20.32 cm)
The length of the ductwork from the dryer to the outside
exhaust outlet, must not exceed 12 feet (3.66 meters).
The
minimum diameter of this ductwork must be at least
8-inches (20.32 cm) even though the dryer exhaust duct
connection is smaller
. Including tumbler/dryer elbow
connections or elbows used for outside protection from the
weather, no more than 4 90° elbows should be used in the
exhaust duct run. If more than the equivalent of four 90°
elbows are used, the cross-sectional area of the ductwork
must be increased.
Multiple Dryer (Common) Venting
IMPORTANT: For extended ductwork runs, the cross-
sectional area of the ductwork can only be increased to an
extent. When the ductwork approaches the maximum
limits as noted in this manual, a professional HVAC firm
should be consulted for proper venting information.
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 duct is added. The minimum diameter of the
individual ductwork must be at least 8-inches (20.32 cm).
IMPORTANT: No more than four dryers should be
connected to one main common duct.
The illustration below shows the minimum cross-sectional
area for multiple dryer round or square venting. These
figures must be increased if the main duct run from the last
dryer to where it exhausts to the outdoors is longer than 12
feet (3.66 meters) or has more than 1 elbow in it.
Multiple Dryer Venting with 8-Inch (20.32 cm) Diameter
720 cfm (20.38 cmm) Exhaust Connections at Common Duct