American Dryer Corp AD-115ES II installation manual

b.Vertical Venting

When possible, it is suggested to provide a separate exhaust duct for each dryer. The exhaust duct should be laid out in such a way that the ductwork travels as directly as possible to the outdoors with as few turns as possible. It is suggested that the use of 90° turns in ducting be avoided; use 30° or 45° angles instead. The shape of the exhaust ductwork is not critical so long as the minimum cross section area is provided.

IMPORTANT: Minimum duct size for a gas, electric, or steam dryer with a vertical run and not more than three (3) elbows (including dryer connection and outside outlets) is 16-inches (40.64 cm) for a round duct or 14-1/2” by 14-1/2” (36.83 cm by 36.83 cm) for a square duct. DUCT SIZE MUST NOT BE REDUCED ANYWHERE DOWNSTREAM OF THE DRYER.

IMPORTANT: Exhaust back pressure measured by a manometer at the dryer exhaust duct area must be no less than 0 and must not exceed 0.3 inches (0.74 mb) of water column (W.C.).

It is suggested that the ductwork from each dryer not exceed 20 feet (6.1 meters) with no more than three (3) elbows for a vertical duct (including the dryer connection and outside outlets). If the ductwork exceeds 20 feet (6.1 meters), or has numerous elbows, the cross-sectional area of the ductwork must be increased in proportion to the length and number of elbows in it. In calculating ductwork size, the cross-sectional area of a square or rectangular duct must be increased by twenty percent (20%) for each additional 20 feet (6.1 meters). The diameter of a round duct should be increased ten percent (10%) for each additional 20 feet (6.1 meters). Each 16-inch (40.64 cm) 90º elbow is equivalent to 36 feet (11 meters) and each 18-inch (45.72 cm) 90º elbow is equivalent to 41 feet (12.5 meters).

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