The following is a quick summary, not to be considered complete list of NFPA 96 codes related to kitchen hoods and exhaust systems:
Ultimate Responsibility
NFPA 96: 4.1.5
The responsibility for inspection, maintenance, and cleanliness of the ventilation control and fire protection of the commercial cooking operations shall be the ultimate responsibility of the owner of the system provided that this responsibility has not been transferred in written form to a management company or other party.
NFPA 96: 4.1.8
All interior surfaces of the exhaust system shall be accessible for cleaning and inspection purposes.
Ductwork and Access Panels
NFPA 96: 5.1.2
Seams, joints, and penetrations of the hood enclosure that direct and capture grease-laden vapors and exhaust gases shall have a liquid tight continuous external weld to the hood’s lower outermost perimeter.
NFPA 96: 7.3.1
Openings shall be provided at the sides or at the top of the duct, whichever is more accessible, and at changes of direction.
NFPA 96: 7.4.1.1
On horizontal ducts, at least one 508 mm x 508 mm (20 in. x 20 in.) opening shall be provided for personnel entry.
NFPA 96: 7.4.1.2
Where an opening of this size is not possible, openings large enough to permit thorough cleaning shall be provided at 3.7 m (12 ft) intervals.
NFPA 96: 7.4.2.2
Where personnel entry is not possible, adequate access for cleaning shall be provided on each floor.
NFPA 96: 7.5.2.1
All seams, joints, penetrations, and duct-to-hood collar connections shall have a liquid tight continuous external weld.
Fan Access Panel
NFPA 96: 8.1.5.3.1
Upblast fans shall be supplied with an access opening of a minimum 76 mm by 127 mm (3 in. by 5 in.) or a circular diameter of 101 mm (4 in.) on the curvature of the outer fan housing to allow for cleaning and inspection of the fan blades.
Electrical Wiring/Fan Hinge
NFPA 96: 7.8.1.1
Rooftop terminations shall be arranged with or provided with the following:
A hinged upblast fan supplied with flexible weatherproof electrical cable and service hold-open retainer to permit inspection and cleaning that is listed for commercial cooking equipment.
NFPA 96: 8.1.1.1
Approved upblast fans with motors surrounded by the airstream shall be hinged, supplied with flexible weatherproof electrical cable and service hold-open retainers, and listed for this use.
NFPA 96: 9.2.1
Wiring systems of any type shall not be installed in ducts.
Rooftop Grease Containment
NFPA 96: 7.8.2.1
Rooftop terminations shall be arranged with or provided with the following:
A removable tray to catch grease out of any traps or low points formed in the fan or duct near the terminal portion of the system into a collection container that is noncombustible, closed, rainproof, and structurally sound for the service to which it is applied and that will not sustain combustion.
A grease collection device that is applied to exhaust systems that does not inhibit the performance of any fan.
NFPA 96: 8.1.1.3
Upblast fans shall have a drain directed to a readily accessible and visible grease receptacle not to exceed 3.8 L (1 gal).
Inspection & Cleaning Frequency
NFPA 96: 11.4 to 11.6.2
The entire exhaust system shall be inspected for grease buildup by a properly trained, qualified, and certified company or person(s) acceptable to the authority having jurisdiction and in accordance with Table 11.4. Upon inspection, if the exhaust system is found to be contaminated with deposits from grease-laden vapors, the contaminated portions of the exhaust system shall be cleaned by a properly trained, qualified, and certified company or persons acceptable to the authority having jurisdiction.
Hoods, grease removal devices, fans, ducts, and other appurtenances shall be cleaned to remove combustible contaminants prior to surfaces becoming heavily contaminated with grease or oily sludge.
Schedule of Inspection (Recommended Intervals May Vary Based on Specific SItuations)
Systems serving solid fuel cooking operations: Monthly inspection.
Systems serving high-volume cooking operations (such as 24-hour cooking, charbroiling, or wok cooking): Quarterly inspection.
Systems serving moderate-volume cooking operations: Semiannual inspection.
Systems serving low-volume cooking operations (such as churches, day camps, seasonal businesses, or senior centers): Annual inspection.
Filters and Fire Suppression
NFPA 96: 6.1.3
Mesh filters shall not be used.
NFPA 96: 6.2.3.1
Grease filters shall be listed and constructed of steel or listed equivalent material.
NFPA 96: 11.1.2
Filter-equipped exhaust systems shall not be operated with filters removed.
NFPA 96: 11.2.1
Maintenance of the fire-extinguishing systems and listed exhaust hoods containing a constant or fire-activated water system that is intended to extinguish a fire in the grease removal devices, hood exhaust plenums, and exhaust ducts shall be made by properly trained, qualified, and certified person(s) acceptable to the authority having jurisdiction at least every six months.
NFPA 96: 10.4
Fusible links and automatic sprinkler heads shall be replaced at least semiannually or more frequently if necessary where required by the manufacturer.
NFPA 96: 11.6.4
Components of the fire suppression system shall not be rendered inoperable during the cleaning process.
NFPA 96: 11.6.7
Cleaning chemicals shall not be applied on fusible links or other detection devices of the automatic extinguishing system.
Solid Fuel Systems
NFPA 96: 14.3.3
Exhaust systems serving solid fuel cooking equipment, including gas or electrically operated equipment, shall be separate from all other exhaust systems.
NFPA 96: 14.4.4
Wall terminations of solid fuel exhaust systems shall be prohibited.
NFPA 96: 14.8.1
The flue or chimney shall be inspected weekly for the following conditions: (1) Residue that might begin to restrict the vent or create an additional fuel source (2) Corrosion or physical damage that might reduce the flue’s capability to contain the effluent.
NFPA 96: 14.8.3.1
The flue or chimney shall be cleaned before these conditions exist.
