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    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.

    UL Listed Grease Filters (Common Sizes)

    H x W Aluminum Galvanized Stainless
    16" x 16" AF1616 GVF1616 SSF1616
    16" x 20" AF1620 GVF1620 SSF1620
    16" x 25" AF1625 GVF1625 SSF1625
    20" x 16" AF2016 GVF2016
    20" x 20" AF2020 GVF2020 SSF2020
    20" x 25" AF2025 GVF2025 SSF2025
    25" x 16" AF2516 GVF2516
    25" x 20" AF2520 GVF2520 SSF2520

    UL Listed Grease Filters, Aluminum (Small)

    H x W P/N
    10" x 16" AF1016
    10" x 20" AF1020
    12" x 16" AF1216
    12" x 20" AF1220

    UL Listed Locking Grease Filters*

    H x W P/N
    20" x 20" LHF2020
    20" x 25" LHF2025
    25" x 20" LHF2520
    *Locking required in Maryland, Virginia, and Washington, DC

    Damaged, missing, or inappropriate grease filters must be replaced with listed grease filters. Your knowledge of how they work, and which ones are needed as replacements, will keep your customer’s cooking operations safe and code compliant.

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    Mark Conroy is an engineer in our Boston, MA office and a member of the NFPA 96 Technical Committee. © 2017 Brooks Equipment.

    Disclaimer: The opinions expressed in the above Tech Series article are the author’s only and provide limited information. Although the information is believed to be reliable, Brooks Equipment Company, LLC expressly disclaims any warranty with respect to the information and any liability for errors or omissions. The user of this article or the product(s) is responsible for verifying the information’s accuracy from all available sources, including the product manufacturer. The authority having jurisdiction should be contacted for code interpretations.