Panel pre-filters made of synthetic & cotton fiber, this kind of filter media can remove particles size about 0.5um with efficiency from 50% to 90%, the synthetic fiber filter can block the large dust and collect it. This process is very important in the normal HVAC systems and cleanroom air systems. As the panel pre-filters already filter large dust, the second filters and third filters no more heavy burden for the large dust.

Filter panel pre-filters thickness can be 21mm, 46mm if the frame is aluminium alloy, filter media thickness can be 10mm, 20mm, 30mm and 40mm; 21mm aluminium alloy with 20mm filter media is the common design, the synthetic filter media is designed with electrostatic absorption ability, this design can help absorb fine dust easily. Other frames such as corrugated paper, and thickness and length, width available, the corrugated paper frame is waterproof and can be used in a moist environment for a long time. Changing the pre panel filters frequently can enlarge pocket filters and HEPA filters service life, the pre panel filters cannot be washable. If wash the filter media, the inside construction may be destroyed. This also can be used as fan coil filters.