14
American Dryer Corp.
113235 - 5
MULTIPLE DRYER (COMMON) VENTING
HORIZONTAL VENTING
If it is not feasible to provide separate exhaust ducts for each dryer, ducts for individual dryers may be channeled
into a common main duct. Each dryer is provided with a back draft damper. The individual ducts should enter
the bottom or side of the main duct at an angle not more than 45º in the direction of the airflow. No more than
eight (8) dryers
should be
connected to one (1) main common duct run.
The main common duct may be any shape as long as the minimum cross-sectional area is provided. The main
duct
should be
tapered with the diameter increasing before each individual 8-inch (20.32 cm) duct is added
(refer to
Illus. C below and Illus. D on page 15
).
Illus. C
Horizontal venting
must not exceed
35 feet (10.7 meters), this calculation compensates for the use of a maximum
of only one (1) elbow, which is the outside outlet protection.
NOTE:
Distance between dryer single ducts being connected to the main common duct
must be
a minimum of 28-1/2” (72.39 cm) dryer width.
Ductwork
should be
laid out in such a manner where allowances are made at rear area of
the dryer for removal of rear service panels or guards.
Illus. C
(refer to the
above
illustration
) shows the minimum cross section area for horizontal multiple dryer
venting. These figures
must be
increased in proportion if the main duct run from the last dryer to where it
exhausts has numerous elbows or is unusually long.
