American Dryer Corp. MDG-120PVV - Manual (Page 20)

18 Maytag Co. 113395 - 6
4. 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 heating, ventilating, and air-conditioning (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.
IMPORTANT: No more than 4 dryers for the MDG-120 and only 3 for the MD-170 should be
connected to 1 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 (3.656 meters) or has more than 1 elbow in it.
A = MDG-120 14-inch (35.56 cm)
MDG-170 18-inch (45.72 cm)
MDS-170 20-inch (50.8 cm)
B = 20 feet (6.10 meters)
Multiple Dryer Venting with 14-inch (35.56 cm) Diameter
2,150 cfm (60.88 cmm) Exhaust Connections at Common Duct
NUMBER OF DRYERS 3 2 1
MINIMUM CROSS-
SECTIONAL AREA
SQ IN 707 531 315
SQ CM 4561 3426 2032
MINIMUM ROUND
DUCT DIAMETER IN 30 26 20
CM 76 66 51
MDS-170
NUMBER OF DRYERS 3 2 1
MINIMUM CROSS-
SECTIONAL AREA
SQ IN 615 455 255
SQ CM 3967 2935 1645
MINIMUM ROUND
DUCT DIAMETER IN 28 24 18
CM 71 61 46
MDG-170
NUMBER OF DRYERS 4 3 2 1
MINIMUM CROSS-
SECTIONAL AREA
SQ IN 455 380 255 115
SQ CM 2935 2452 1645 742
MINIMUM ROUND
DUCT DIAMETER IN 24 22 18 14
CM 60 55 45 35
MDG-120
Multiple Dryer Venting with 18-inch (45.72 cm) Diameter
3,700 cfm (104.77 cmm) Exhaust Connections at Common Duct
Multiple Dryer Venting with 20-inch (50.8 cm) Diameter
4,400 cfm (124.59 cmm) Exhaust Connections at Common Duct
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.