Electronic air cleaners used in a HEPA filtration system offer a higher degree of removal efficiency at lower average lifetime pressure drop than in the traditional arrangement. Electrostatic prefilters for cleanrooms reduce energy consumption by removing the dust and particles from the air stream before they can load the HEPA filters. This increases HEPA filter life and can increase the HEPA filter's efficiency rating to an ULPA filter level. [McIlvaine, 1992]
McIlvaine et al. (1992), says that when used with cleanroom HEPA filters, "Electrostatic systems of various types have been shown to significantly enhance the efficiency of the usual fiber filter media. Not only does efficiency increase, pressure drop decreases and filter life is extended by about a factor of 3."
