Pocket bag air filters can be made of synthetic pocket bag filter material or pocket synthetic fiber media blended with active carton, as well as the fiber glass pocket bag filter materials with various filter efficiency, mainly from F5~F9 (CRAA 430) or EU5~EU9 (EN779) or MERV9~MERV15 (ASHRAE). The pocket bag filters often installed in HVAC systems, so also called HVAC pocket bag air filter, which is designed for industrial and commercial applications as well as for residential use to boost indoor air quality. Sometimes, the pocket bag air can be used for the first stage of the HVAC systems, but mostly will used as a secondary or final filter that behind a pleated primary filter. The pocket bag filter material was adopted the nonwoven filter material with the relevant filter efficiency, for improve the dust loading and reduce the air resistance, the filter pockets will be divided into several small spaces, all the synthetic material will sealed with heat welding and the fiber glass will be sewn by sewing thread but the seam will be sealed with thermoplastic so as to guarantee the filter efficiency at the right requested data.
