Difference between revisions of "Restaurant Hood Systems and Fire Suppression"

Revision as of 14:23, 3 July 2008

Restaurant and kitchen hood fire suppression systems are required by law to be inspected, serviced, tested and certified at semi annual intervals. Outdated equipment must be made current to comply with fire code laws.

Restaurant Grease Hood

terminology keywords: Stainless Steel, Kitchen Exhaust Hood, Grease Hood, Galvanized Restaurant Grease Hood, Box Exhaust Canopy

The National Fire Code (NFC) dictates that the Hood should be 6 inches larger on all sides compared to all of the equipment that is under it.

Canopy hoods are now commonly constructed of 16 and 18 gauge steel. Joints are welded liquid tight without seams, utilizing an automatic wire feed mig welder.

Hood to Fan Ductwork

terminology keywords:

Code in many states requires 18 gauge ductwork if it is steel, 22 gauge if it is stainless. Galvanized ductwork can be at a minimum gauge of 18 as long as it can be welded. 16 gauge is sometimes used because it is easier to weld the seams. Welded grease tight seams are required; all external seams to be welded liquid tight.

Some good quality duct work has integral grease troughs run the length of the hood with removable grease catch cups. A common type of duct work inside the building (not exposed to weather) is 16 gauge hot rolled carbon steel with all seams and joints welded liquid tight. Exterior ductwork (exposed to weather) is 16 gauge galvanized steel fabricated in the same manner.

Exhaust duct to hood connections should use a bolt/flange type with high temperature (1500 degree) gasket. The ductwork should be sized to provide a minimum of 1500 fpm and a maximum of 2200 fpm air flow.

The Uniform Mechanical Code states that a Type II Hood must have a duct that is constructed of rigid metallic materials of al least 0.024-inch (.0.61) (No.24 gage) thick. The Uniform Mechanical Code states that a Type I Hood must have a duct that is specifically designed for Grease laden air. The duct shall be constructed of at least. o55-inch-thick (1.40mm) ( No. 16 manufacture's standard gage) steel or stainless steel at least .044 inch (1.10mm) in thickness continuously welded and water tight.

Hood Exhaust Fan

terminology keywords: Upblast Exhaust Fan, Exhaust Vent, Direct Drive Centrifugal Upblast Exhaust Fan

Make Up Air Supply Fan

terminology keywords: Return Air, Make Up Air Vent

Make-up Air (MUA) Fans blow air into the facilities to compensate (make-up) for the air being pulled out by the Exhaust Fan.

Hood Fire Suppression

terminology keywords: Ansul Suppression System, Wet Chem, Piro-Chem, Range Guard

New UL 300 compliant wet chemical fire suppression systems are now required to be installed for the protection of the hood plenum area. Most modern fire suppression systems include a mechanical gas shut-off valve (mentioned below) and an electronic micro switch is supplied with the system.

Portable Fire Extinguisher

terminology keywords: Potassium Acetate Agent

Fire extinguishers designed specifically for kitchens are now available from most suppliers. A survey prepared by the National Association of Fire Equipment Distributors recently revealed that hand operated portables extinguished over 90% of the fire incidents in commercial facilities. In most cases the fire was completely extinguished before fire department personnel arrived on the scene.

Gas Valve Cut Off

terminology keywords: Gas Valve, Gas Valve Disconnect, Mechanical Shutoff Valve, Ansul Gas Valve

Shuts off gas to cooking equipment in the event of fire.