18-28-504.9.4.1 Specified length.
   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. Where fittings are used, the maximum length of the exhaust duct shall be reduced in accordance with Table 18-28-504.9.4.1.
Table 18-28-504.9.4.1
Dryer Exhaust Duct Fitting Equivalent Length
Dryer Exhaust Duct Fitting Type
Equivalent Length
4" radius mitered
45-degree elbow
2 feet 6 inches
4" radius mitered
90-degree elbow
5 feet
6" radius smooth
45-degree elbow
1 foot
6" radius smooth
90-degree elbow
1 foot 9 inches
8" radius smooth
45-degree elbow
1 foot
8" radius smooth
90-degree elbow
1 foot 7 inches
10" radius smooth
45-degree elbow
9 inches
10" radius smooth
90-degree elbow
1 foot 6 inches
 
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 degree = 0.0175 rad.
(Amend Coun. J. 9-14-21, p. 35949, Art. V, § 11)