Maytag MC2 - Manual (Page 24)

If it is not feasible to provide separate exhaust ducts for each dryer, ducts from the individual dryers may be
channeled into a common main duct. Each 100 lb. dryer must be 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 45 degrees and
should be spaced at least 46-1/8 inches apart. (Figure 7) The main duct should be tapered with the
diameter increasing before each individual duct is added.
On 100 lb. dryers, the minimum increase in cross section area should be 115 square inches for each 12 inch
duct added and 205 square inches for each 16 inch duct added. Where rectangular main ducting is used, the
areas shown should be increased 10 square inches and the ratio of the duct width to depth should not be
greater than 3-1/2 to one. Figure 7 shows the minimum cross-section areas of the main duct for either 12
inch or 16 inch dryer ducts. These figures should be increased if the main duct is unusually long (20 feet or
over) or has numerous elbows in it.
Inadequate exhaust facilities may cause high temperature limit switches or air flow switches to shut off the
dryers. DO disable the switches, which are provided for your safety. Instead, investigate the exhaust
ducting. Any obstruction or air flow friction due to numerous elbows/fittings in the ducting will slow the
passage of air through the system with resulting inefficiency and potential fire hazard.
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