Smoke ventilation (Dutch: brandventilatie) is the controlled removal of smoke and heat from a building during a fire to maintain tenable conditions for evacuation and fire-fighting operations. By extracting hot smoke from the upper zone, it preserves a clear layer of breathable air near floor level.
Types of smoke ventilation
- Natural smoke ventilation — relies on buoyancy: hot smoke rises and exits through openings in the roof or high in the facade, while fresh air enters at low level
- Mechanical smoke ventilation — uses powered fans and ductwork to extract smoke, regardless of wind conditions or building geometry
- Hybrid systems — combine natural intake with mechanical extraction, or vice versa, to suit specific building layouts
Key components
- Smoke vents or exhaust fans — the primary extraction points, sized to handle the expected smoke volume
- Inlet openings — allow replacement air to enter at low level, preventing negative pressure that would stall extraction
- Smoke curtains or barriers — form reservoirs that contain smoke within a defined zone and prevent it from spreading horizontally
- Control systems — activated automatically by smoke detectors or manually by the fire service
Application
Smoke ventilation is required in many building types including shopping centres, car parks, atriums, industrial halls, and high-rise stairwells. Building regulations specify the minimum free aerodynamic area for natural systems or the extraction capacity in cubic metres per hour for mechanical systems. Proper smoke ventilation significantly improves the safety of escape routes and allows fire fighters to locate and attack the fire more effectively.
Related Terms
- Fire prevention
- Fire resistance
- Fire spread
- Smoke curtain
- Escape route
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