Bosch HMV3061U Installation Instructions - Page 29

Hood exhaust When venting exhaust to the oustside, hood exhaust ducts will be required. Read the following carefully. Note:ĄIt is important that venting be installed using the most direct route and with as few elbows as possible. This ensures clear venting of exhaust and helps prevent blockages. Also, make sure dampers swing freely and nothing is blocking the ducts. Exhaust connection The hood exhaust has been designed to mate with a standard 3¼" x 10" (82 x 254 mm) rectangular duct. If a round duct is required , a rectangularĆtoĆround transition adaptor must be used. Do not use less than a 6" (152 mm) diameter duct. Maximum Duct Length For satisfactory air movement, the total duct length of 3¼" x 10" (82 x 254 mm) rectangular or 6" (152 mm) diameter round should not exceed 120 equivalent feet (36,5 m). Elbows, transitions, wall and roof caps etc. cause additional resistance to airflow and are equivalent to a section of straight duct which is longer than their actual physical size. When calculating the total duct length, add the equivalent lengths of all transitions and adaptors plus the length of all straight duct sections. The chart below shows you how to calculate total equivalent ductwork length using the approximate feet of equivalent length of some typical ducts: Duct Pieces Equivalent Length x Number used Equivalent Length RectangularĆtoĆRound Transition Adaptor* 5 ft (1,5 m) x ( ) = ft or m Wall Cap 40 ft (12,2 m) x ( ) = ft or m 90º Elbow 10 ft (3 m) x ( ) = ft or m 45º Elbow 90º Elbow 45º Elbow Roof Cap 5 ft (1,5 m) x ( ) = 25 ft (7,6 m) x ( ) = 5 ft (1,5 m) x ( ) = 24 ft (7,3 m) x ( ) = ft or m ft or m ft or m ft or m 29