Choosing between a fire damper and a smoke control damper isn’t a minor detail.
It’s a critical life-safety decision.
They are not interchangeable. They are tested to different standards. They operate differently. And they solve different problems.
With the Building Safety Act raising accountability and BS 9999 and BS 9991 reshaping fire strategies, specifying the correct system is essential. Get it wrong and you risk compliance failures, compromised safety and costly remediation.
This guide explains the difference clearly, so you can specify with confidence.
The Core Difference, In Simple Terms
Fire dampers are designed to maintain fire compartmentation.
They are typically installed where ventilation ductwork passes through a fire compartment barrier. In a fire condition, they close to prevent fire from spreading through the duct system.
All fire dampers fail safe closed on activation.
Their role is containment.
Smoke control dampers also maintain compartmentation when closed.
However, during a fire they perform a different function:
They open on the fire floor to remove smoke from escape routes.
All other dampers in the system remain closed to maintain compartmentation.
Their role is to control smoke extraction from the fire floor, ensuring safe evacuation and access for fire services.
Unlike fire dampers, smoke control dampers are active systems.
They do not have a fail safe position and require a protected power supply to operate during a power failure.
Why the Distinction Matters
Fire dampers contain fire.
Smoke control dampers manage smoke movement.
Different purpose.
Different operation.
Different testing standards.
Understanding this distinction is fundamental to compliance and to building performance in a real fire scenario
Fire Dampers (FD)
Mechanical fire dampers automatically close when temperature rises during a fire. This prevents the fire from breaching a compartment via ductwork.
Compliance & Testing
In accordance with Approved Document B:
- Required to be E rated for fire integrity
- Conform to BS EN 15650
- Minimum E classification of 60 minutes, or to match the integrity rating of the fire resisting element — whichever is higher
- Tested to BS EN 1366-2
- Classified to BS EN 13501-3
How They Operate
Typical features include:
- A mechanical thermal fuse or fusible link activating at approximately 72°C
- Blade(s) or curtain mechanism closing to seal the duct at the fire barrier
The result: maintained compartment integrity.
BSB Fire Damper Range
BSB’s FD-C, FD-R and FD Series dampers are fully third-party tested and certified, supporting both life safety and building protection
.
Motorised Fire Dampers (MFD)
Motorised fire dampers provide early closure through detection system integration.
They comprise a single or multi-blade damper fitted with a fail safe closing actuator.
How They Operate
- Actuator closes the damper upon smoke or fire detection system input
- Provides early closure to limit smoke and fire spread
- Includes a duct-mounted thermal probe as secondary protection, triggering at 72°C
Compliance & Testing
- Conform to BS EN 15650
- Minimum ES classification of 60 minutes, or to match the integrity rating of the fire resisting elements — whichever is higher
- Tested to BS EN 1366-2
- Classified to BS EN 13501-3
Motorised fire dampers remain a passive fire protection component. Their purpose is containment for a specified duration, protecting escape routes and critical zones such as sleeping risk areas
.
BSB Motorised Fire Damper Range
BSB’s FSD-C, FSD-TD and AT-FSD Series are available with:
- 24V or 230V actuators
- Electro-mechanical or addressable control panel solutions
- Full third-party testing and certification
Designed for guaranteed performance in life safety applications, with reduced smoke leakage (S) limiting the spread of smoke through ducted ventilation systems
.
Smoke Control Dampers
Smoke control dampers are fundamentally different.
They are active control devices forming part of an engineered smoke control strategy.
Their purpose is to control, limit or redirect smoke movement in the early stages of a fire while maintaining compartmentation when closed.
How They Operate
During a fire:
- The damper on the fire floor automatically opens (via cause and effect)
- Smoke is extracted from the affected area
- All other dampers remain closed to prevent smoke spread
They are motorised with motor open / motor closed actuators to enable automatic or remote operation.
They are triggered by smoke or fire alarm sensors and require a protected power supply to operate during power failure.
They do not have a fail safe position.
Compliance & Testing
Smoke control dampers:
- Are fire resistance tested to BS EN 1366-10
- Multi compartment tested to BS EN 12101-8
- Classified according to BS EN 13501-4
They form part of a complete engineered smoke control strategy, helping to maintain visibility for evacuation, enable fire service access and support safe means of escape
When Specifying Ask These Questions
- Is the requirement containment only?
→ Specify a fire damper
- Is the requirement for E or ES rating?
→ Check damper classification
- Is the strategy based on engineered smoke extraction?
→ Specify a smoke control damper.
- Is the smoke control damper required for single or multi compartment
→ Check damper classification
- Is fail safe closure required?
→ Fire damper or motorised fire damper
Clear strategy equals correct product.
