Airport Terminal Smoke Zoning: NFPA 415, NFPA 92 and Very High Ceilings

With 40 m ceilings, huge atria and more than 10,000 passengers an hour, an airport terminal is one of the most demanding smoke control scenarios. On a project of this scale we have to apply NFPA 415 (terminal buildings) and NFPA 92 together: one addresses fuel and fire risk, the other smoke control in large volumes. Well-designed zoning keeps smoke in the zone where it starts, so it does not travel to a gate 300 m away.

Smoke Zoning Logic

• Zone size: Maximum 2,000 m² or 60 m in length/width; beyond that the exhaust rate becomes unmanageable.
• Smoke curtain: Automatic curtain dropping 2–3 m from the ceiling to separate the zone physically in a fire.
• Each zone: Independent exhaust and makeup air; one should not serve as the other’s backup.
• Check-in, gates, baggage drop: Planned as separate zones from the outset.

Smoke Exhaust Calculation for a Very High Ceiling

A typical scenario: 40 m ceiling, 2,000 m² zone, 5 MW design fire, smoke layer interface 30 m above the fuel:

• NFPA 92 axisymmetric plume: m = 0.071 × 5000^1/3 × 30^5/3
• m = 0.071 × 17.1 × 289.6 ≈ 352 kg/s
• Volumetric flow: ~1,000,000 m³/h (for a single zone)
• Fan group: 10 × 100,000 m³/h (this only meets the demand; standby units must be added)
• A common solution: normal ventilation uses the same fans (dual-use design)

NFPA 415 and Jet Fuel Risk

• Baggage area: Gas cartridges or small canisters in luggage are not unlikely and are considered in the fire load.
• Gate area: Kept at least 15 m inside from the aircraft refueling point.
• Jet A/A-1: Flash point >38 °C; Class II combustible liquid.
• Apron: A separate drainage line and oil-water separator for fuel spills are mandatory.
• Gate monitor: Fixed AFFF monitor rated at 10,000 L/min.

Sprinklers in the Check-in Area

• High ceiling: ESFR is not a solution under a 40 m ceiling (NFPA 13 Table 23.3.1 limits ESFR to a 13.7 m ceiling); at this height ceiling sprinklers alone are not enough, so a performance-based analysis is needed.
• Service/control areas: OH2; standard K8.0 (K115) sprinklers are usually sufficient.
• Under baggage belts: Tunnel sprinklers, OH2, at 2 m spacing.
• Security X-ray screening: Water mist or a clean agent such as FM-200 is preferred to protect the electronics.

Istanbul New Airport Example

• 1.4 million m², the world’s largest terminal building under a single roof
• 250+ smoke zones
• CFD: FDS and Pathfinder, a mesh of more than 1 billion cells
• Large atrium: 40 m facade and an 18 m atrium void across 7 levels

Terminal smoke with MEP Calc

MEP Calc sizes airport terminal smoke zones, 40 m ceiling plume flow and mega AHU banks per NFPA 415/92.

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SprinkCalc covers hazard classification, design density and area, K-factor selection, water demand and hydraulic calculations for NFPA 13, FM Global and BS EN 12845 in a single iOS app, and exports a professional PDF report. One of the few tools that unifies all three major fire protection standards.

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