American Dryer Corp. ML-170 - Manual (Page 15)

113360 - 8 www.amdry.com 15
NOTE 1 Opening 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.
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 45° in the direction of the flow and should be spaced at least 55-3/4” (141.61 cm) apart. The main duct
should be tapered, with the diameter increasing before each individual 18-inch (45.72 cm) duct is added.
IMPORTANT: The dryer is not provided with a back draft damper. When exhausted into a multiple
(common) exhaust line, a back draft damper must be installed at each dryer duct.
IMPORTANT: No more than three (3) dryers should be connected to one (1) main common duct.
The illustrations on the next page show the minimum cross section area for multiple dryer round or square
venting. These figures must be increased in proportion if the main duct run from the last dryer to where it exhausts
to the outdoors exceeds 20 feet (6.09 meters) or has more than one (1) elbow in it.
IMPORTANT: When the ductwork approaches the maximum limits as noted in this manual, a professional
HVAC firm should be consulted for proper venting information.
IMPORTANT: Exhaust back pressure measured by a manometer in the exhaust duct must be no less than 0
and must not exceed 0.3 inches (0.74 mb) of water column (W.C.).
IMPORTANT: When the ductwork approaches the maximum limits as noted in this manual, a professional
heating, ventilating, and air-conditioning (HVAC) firm should be consulted for proper venting
information.