1. A Case Study for Smoke Exhaust Flow Rate
Due to the leakage of fire damper and smoke duct, it is a mistake to design both the flow rate of smoke
exhaust fan and the required smoke exhaust flow rate with the same value. Flow arte of smoke exhaust fan
should be greater than that of the required smoke exhaust flow rate. Based on detailed calculation, the follow-
ing case study is presented. As the flow velocity in the smoke exhaust duct is 10 m/s with Class-I smoke
damper, the flow rate of smoke exhaust fan is about 4.52m3/s. This number could be increased to 5.62m3 /s if a
Class-III damper is selected. And if the smoke exhaust shaft is used, instead duct, the flow rate of smoke
exhaust fan could even be increased to 8.72m3/s, although in such a case the flow velocity is decreased. Even a
Class-I smoke damper is used in such case, the flow rate of exhaust smoke fan increases to 4.78m3/s.