The effect of pleat count and air velocity on the initial pressure drop and fractional efficiency of HEPA filters

The importance of clean air to the well-being of people and industrial applications has highlighted the critical role of air filters performance. Accurate filter performance prediction is important to estimate filter lifetime and reduce energy and maintenance operating costs. To ensure appropriate filter selection for a specific application, the effect of pleat count and surface area on filter design and performance has been investigated. This paper examines the effects of air velocity on permeability during operation of HEPA pleated V-shaped filters, and the effect of pleat count on the initial pressure drop and fractional efficiency using DEHS testing according to DIN 1822. An empirical equation for predicting the efficiency of the filter is suggested.