The SFC downflow cartridge dust collector from United Air Specialists uses MERV 15 filter cartridges — one of the most efficient in the industry — as standard. These Protura® Nanofiber filters are highly efficient on particles in the 0.3 to 1 micron size range and the patented filter cleaning system and nanofiber cartridge filters allow SFC systems to be designed with higher air-to-media ratios, which may reduce the size of the collector for savings in floor space. The DPC triggers filter cleaning when differential pressure in the collector reaches a high point selected by the operator.