Grease Filters: Crucial Components of Kitchen Grease Removal Systems

By Mark Conroy

Capturing and removing grease in commercial kitchens reduces the fire hazard. Filters are the most crucial component of the grease removal system, as they capture the grease and direct it to a safe collection point. Having the right ones in place will keep your customer’s cooking operations safe and code compliant.

Grease removal devices are required to be installed in kitchen hoods, and grease filters are used almost exclusively for this purpose. NFPA 96, Standard for Ventilation Control and Fire Protection of Commercial Cooking Operations requires the grease filters to be listed to UL 1046, Standard for Grease Filters for Exhaust Ducts. Independently installed mesh filters are prohibited, as they do not meet NFPA 96 or UL 1046. A mesh filter can only be used if it has been evaluated as an integral part of a listed hood or if it is listed for use in conjunction with a primary filter (96, 6.1.3).

Grease filters incorporate metal baffles. The cooking vapors are drawn through filters by the exhaust fan. Since the metal filters are relatively cooler than the vapors, much of the grease condenses and settles on the filters. They are installed at an angle of at least 45 degrees, so the grease flows to drip trays at the bottom of the filters. Metal containers at the ends of drip trays must be emptied frequently by kitchen staff. When grease filters are frequently cleaned (typically in a dishwasher) and the containers are emptied frequently, the fire hazard is reduced significantly.

Filters not only reduce the accumulation of grease in the ductwork, but a clean filter acts as a fire barrier for cooking flare-ups. Clean filters will typically keep these flames from reaching the surface of exhaust ducts, so small flare-ups usually will not spread fire throughout the ductwork. Clean, undamaged, and properly installed listed grease filters are extremely important for fire protection.