Greenhouse Fire: NFPA 1, Polycarbonate and CO₂ Enrichment

Turkey's 35,000 ha of greenhouses produce about 7 Mt a year, much of it for the EU. Modern greenhouses use polycarbonate or PE film covers with propane/LPG heaters plus CO₂ enrichment. NFPA 1 treats the plastic cover as a Class A fire load and requires heater clearances and LPG tank setbacks.

Fire Load

• PE film: 4–6 MJ/m²; drips and spreads fast once ignited
• Polycarbonate: UL 94 V-2, tends to self-extinguish
• Glass: non-combustible, but breaks and falls at high temperature
• Wood frame: 20–40 MJ/m², the heaviest fire load in the greenhouse
• Plants: light, wet load; dry leaves on mature plants raise the risk

Heater Risk

• LPG tank: NFPA 58 setback 3 m
• Propane unit heater: 1 m clearance
• Biomass boiler: NFPA 85 smoke and flue gas control
• Cogeneration: gas engine exhaust used as CO₂ source, with double checks
• Flue gas scrubber: CO below 50 ppm in the gas supplied to plants

CO₂ Enrichment

• Level: 800-1,500 ppm
• Source: flue gas recovery or liquid CO₂
• Monitor: 5,000 ppm personnel alarm
• Ventilation: 60 ACH against low oxygen
• OSHA TLV: 5,000 ppm TWA

Greenhouse Ventilation

• Ridge vent: opening of 15–30% of floor area
• Pad and fan: indoor air speed about 1.2 m/s
• 30% open surface: lower limit for natural ventilation
• Shade screen: 50% sun reduction
• Heat removal: 80% efficiency targeted in the ΔT calculation

Historic Cases

• Propane leak fire: propane leak fire destroyed 10 decares
• Netherlands greenhouse region: 12,000 ha world lead
• Netherlands: biomass boiler explosion destroyed adjacent blocks
• US cannabis greenhouses: fires from solvent (hexane/butane) extraction
• Canadian greenhouses: major losses from heater clearance violations

Greenhouses with MEP Calc

MEP Calc sizes greenhouse ventilation 30 percent ridge vent, pad fan 1.2 m/s, CO2 1,500 ppm fertigation and NFPA 1 LPG tank setback 3 m.

Download MEP Calc on the App Store

SprinkCalc — Fire Sprinkler Design Across Three Standards

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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