504.8.4.1 Specified length.
MC § 504.8.4.1
The maximum length of the exhaust duct shall be 35 feet (10 668 mm) from the connection to the transition duct from the dryer to the outlet terminal or to a common or central exhaust system. Where fittings are used, the maximum length of the exhaust duct shall be reduced in accordance with Table 504.8.4.1. Table 504.8.4.1Dryer Exhaust Duct Fitting Equivalent Length a Dryer Exhaust Duct Fitting Type Equivalent Length Dryer Exhaust Duct Fitting Type Equivalent Length 4" radius mitered 45-degree elbow2 feet 6 inches 4" radius mitered 90-degree elbow5 feet 6" radius smooth 45-degree elbow1 foot 6" radius smooth 90-degree elbow1 foot 9 inches 8" radius smooth 45-degree elbow1 foot 8" radius smooth 90-degree elbow1 foot 7 inches 10" radius smooth 45-degree elbow9 inches 10" radius smooth 90-degree elbow1 foot 6 inches For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 degree = 0.0175 rad. a. The equivalent length column of the table indicates how much length must be added to the exhaust duct total length for each fitting used.
