2024-03-04
wire mesh fence-Grease Filters / Exhaust Hood Guide According to NAFA
Type 1 hood exhaust filters shall be equipped with approved grease baffle filters or grease extractors designed to remove grease from the exhausted air. The most common air filters to remove grease currently in use are the baffle-type air filters. Baffle-type filters simplify the cleaning process since most of the grease deposits run off the baffles to a collection device. The older style mesh-type air filters are not acceptable in new installations. NFPA 96, ANSI NFS Standard 2, and UL 1046 no longer recognize the old style mesh type air filters. They may present a fire hazard and decrease airflow as they become clogged with grease. Grease filters and extractors shall be of such size, type, and arrangements as will permit the required quantity of air to pass through such units at rates not exceeding those for which the air filter or extractor was designed and approved. The optimum operating velocities, measured in feet per minute (FPM), vary from filter to filter. Therefore, the manufacturers should be consulted to obtain the appropriate rates for each specific air filter. It is important to select the proper number of grease filters for the hood. Too few filters increase the resistance to airflow and raise the air filter cleaning frequency.