Performance Evaluation Of Commercial Air-Cleaning And High-Efficiency Filter Media, 1996 Nonwovens Conference Proceedings

Ming Ouyang, Benjamin Y. H. Liu, and

Kenneth L. Rubow

University of Minnesota

A semi-automated test system has been developed, using standard equipment, for easy and accurate measurement of the collection efficiency and pressure drop of filters for high efficiency and general purpose air cleaning. The possible errors and uncertainties in filter efficiency measurement have been evaluated and minimized through planned system design and operation. Using this system, pressure drop and filter efficiency data for seven commercially available, high-efficiency and ventilation filter media have been obtained. The filter face velocity was varied from 2 to 20 cm/s and the particle diameter, from 0.03 to 0.5 µm. At the standard filter face velocity of 10.5 ft/min (5.33 cm/s), the measured filter efficiency was found to range from a low of 9.9% at 0.1 µm for an ASHRAE grade filter with ASHRAE efficiencies of 40 - 50%. to 99.9973% at 0.1 pm for the ULPA grade filter. For the filters tested, the most penetrating particle size was found to lie in the range between 0.1 - 0.2 µm at the standard face velocity of 10.5 ft/min (5.33 cm/s). The most penetrating particle size has been found to decrease with increasing filter face velocity and increase with decreasing face velocity.