
If practical, it is best to locate the appliance to permit the use of shorter horizontals and fewer elbows. -Two 90° elbow, maximum total horizontal length of 20 ft (6m). -Three 90° elbow, maximum total horizontal length of 13 ft (3.8m). -Four 90° elbow, maximum total horizontal length of 6 ft (1.9m). -Five 90° elbow, maximum total horizontal length of 0 ft (0m). If 45° elbows are used, one 90° elbow is equivalent to two 45° elbows. Venting rise should be a minimum of 1 ft (.31m). from the top o