Passive Fire Protection

When does code require a fire damper vs. a smoke damper vs. a combination damper in ductwork?

IBC and NFPA 90A trigger a fire damper at every duct penetration of a fire-rated wall, floor, or shaft. Smoke dampers are required where ducts cross smoke barriers or where an engineered smoke-control system needs to compartmentalize. Combination fire/smoke dampers consolidate both functions and are the default in assemblies that are both rated and smoke barriers — typically corridor walls and shaft enclosures in high-rise construction.

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