NFPA 96: Commercial Kitchen Ventilation

Overview

NFPA 96 is the standard for ventilation control and fire protection of commercial cooking operations. This comprehensive standard addresses the design, installation, operation, inspection, and maintenance of all components in commercial kitchen exhaust systems including hoods, ducts, fans, and fire suppression equipment.

The 2021 edition includes updated requirements for solid fuel cooking, recirculating systems, and enhanced cleaning frequencies based on cooking volume. NFPA 96 works in conjunction with UL 300 for suppression system requirements and local mechanical codes.

Hood Requirements

NFPA 96 specifies detailed requirements for exhaust hood design and installation:

• Type I Hoods: Required for cooking equipment producing grease-laden vapors
• Type II Hoods: For equipment producing heat and steam but no grease vapors
• Overhang Requirements: Minimum 6 inches beyond equipment on all open sides
• Hood Height: Maximum 4 feet above cooking surface for wall-mounted canopy hoods
• Exhaust Rate: Minimum airflow rates based on hood type and cooking equipment
• Grease Filters: Listed baffle or mesh filters, readily removable for cleaning
• Materials: Steel minimum 0.043 inches thick or stainless steel 0.037 inches

Duct System Design

Exhaust duct construction and installation requirements:

• Material: Welded steel minimum 16 gauge for ducts up to 18 inches
• Joints: Continuously welded with liquid-tight external welds
• Slope: Minimum slope of 1/4 inch per foot toward hood or grease reservoir
• Clearances: 18 inches from combustible materials, reduced with approved insulation
• Access Panels: Required every 12 feet and at changes in direction
• Termination: Minimum 40 inches above roof with approved termination device
• Velocity: Minimum 1,500 feet per minute to prevent grease accumulation

Fire Suppression Integration

NFPA 96 requires automatic fire suppression systems for most commercial cooking operations:

• UL 300 Systems: Required for all cooking equipment producing grease-laden vapors
• Coverage Areas: Cooking equipment, hood interior, and duct collar
• Activation: Automatic via fusible links and manual pull stations
• Fuel Shutoff: Automatic gas and electrical shutoff upon system activation
• Portable Extinguishers: Class K extinguishers required within 30 feet
• System Reset: Professional reset required after any activation
• Integration: Connection with building fire alarm system required

Cleaning & Maintenance

NFPA 96 mandates specific cleaning frequencies based on cooking volume:

• Monthly: Systems serving solid fuel cooking operations
• Quarterly: High-volume operations (24-hour cooking, charbroiling, wok cooking)
• Semi-Annual: Moderate-volume operations (6-16 hours daily)
• Annual: Low-volume operations (seasonal, churches, senior centers)
• Cleaning Scope: Hoods, filters, ducts, fans, and all accessible areas
• Documentation: Cleaning certificates posted showing date and company
• Standards: Cleaning to bare metal per IKECA or NFPA 96 guidelines

Inspection Requirements

Regular inspections ensure system safety and code compliance:

• Initial Inspection: Complete system inspection before first use
• Monthly: Visual inspection of hood, filters, and accessible ducts by staff
• Quarterly: Professional inspection of high-volume systems
• Annual: Comprehensive inspection by qualified professional
• Documentation: Maintain inspection records for authority having jurisdiction
• Deficiency Correction: Immediate correction of fire hazards required
• Certification: Annual certification of compliance typically required