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503806
4. Make-Up Air Requirements
A dryer exhausts 214 CFM (measured at back of dryer) and sufficient
make-up air must be supplied to replace air exhausted by each dryer.
An unobstructed opening of at least 40 square inches (260 cm
2
) of
outdoor make-up air MUST be provided for each dryer. Protective
louvers in the opening to the outdoors can reduce air movement
approximately 35 to 40 percent. Be sure the opening is large enough to
compensate for any louvers.
If it is necessary to duct make-up air to the dryer, increase the area of
the ductwork by 25 percent to compensate for any reduction in air
movement. In addition, the make-up air duct should extend down to
within approximately two feet from the floor, directly behind the dryer.
DO NOT use sheet metal screws on exhaust pipe joints or
other fastening means which extend into the duct that could
catch lint and reduce the efficiency of the exhaust system.
Secure all joints with duct tape.
(continued)
