Duct Penetration

Question

Is a duct which penetrates a required 1 hr. fire-rated partition required to be equipped with a fire damper? (Paul Sullivan claims he was asked this one three times in one day!!)

Discussion

Only sometimes. The complete answer can be found in MSBC 709.6.4 , exception 3, which states that "In penetrations of walls with a required one-hour fireresistance rating or less by a ducted HVAC system in areas of other than Use Group H where the building is equipped throughout with an automtic sprinkler system in accordance with 780 CMR 906.2.1" a fire damper is not required.