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Apprentice Q&A · #071

What is the difference between a dynamic and a static fire damper?

2nd YearDampersRED · Stop / Verify

Dynamic Fire Damper: Rated to close securely while the HVAC system fan is actively running and pushing high-velocity air through the system. Features a heavy spring-assisted closure system. * Static Fire Damper: Rated to drop shut purely via gravity once the system fan shuts down entirely. It cannot close safely against active system velocity.

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Plain-English answer

Dynamic Fire Damper: Rated to close securely while the HVAC system fan is actively running and pushing high-velocity air through the system. Features a heavy spring-assisted closure system. * Static Fire Damper: Rated to drop shut purely via gravity once the system fan shuts down entirely. It cannot close safely against active system velocity.

Field checklist

Ask Foreman

Hey boss, I’m on dampers and need verification before I touch this: What is the difference between a dynamic and a static fire damper? Do you want me to stop here and check the approved detail, submittal, or inspector/manufacturer requirement first?

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Verify before acting

Use this as training guidance. The foreman, approved drawings, project specs, manufacturer installation instructions, employer safety policy, and AHJ/code requirements always control the final answer.

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