Fire Dampers — Types, Ratings and Installation

What it is

A closure device inside ductwork at the point it crosses a fire compartment boundary, restoring the fire resistance of the wall or floor it passes through.

Types

Type	Actuation	Typical use
Fire damper	Fusible link, heat	General compartment crossings
Fire-smoke damper	Motorised, alarm signal	Escape routes, pressurisation
Smoke damper	Motorised, detection	Smoke control systems
Ceiling radiation damper	Heat	Ceiling penetrations in rated floors

Specification at a glance

Property	Typical specification
Rating	Matches the wall or floor rating — 60, 120 minutes
Standard	EN 15650 or UL 555
Link temperature	Commonly 72°C for fire dampers
Frame	Purpose-made installation frame, built into the wall
Actuator	Spring-return on motorised types
Access	Panel sized and positioned to reach the damper

Installation is where the rating lives

A correctly rated damper installed badly gives no protection at all:

• The damper must be built into the wall on its installation frame, not hung off the duct beside it
• The gap around the frame must be fire-stopped with a tested system
• The duct must be able to fall away in a fire without pulling the damper out
• An access panel must reach the damper for testing and resetting
• Links and blades must be clear of paint and free to move

Where projects go wrong

• No access panel. The damper can never be tested or reset.
• Fixed to the duct, not the wall.
• Fire stopping done with general-purpose sealant rather than a tested system.
• Rating lower than the wall it penetrates.
• Fire-smoke damper specified but wired to nothing, so it never closes on alarm.

Standards referenced

Compartmentation and services provisions under NBC 2016, Part 4. Fire damper requirements under EN 15650 and UL 555.