Gaps between filters can cause significant decreases in filter efficiency.

Proper filter installation is a key ingredient in ensuring filter effectiveness. Gaps between filters can create pathways for entry of major quantities of particles.

Dr. Jeffrey Siegel of the University of Texas at Austin has found that a 10-millimeter gap between filters can substantially drop the MERV rating of a filter system. In a presentation to the National Air Filtration Association (NAFA) in April Dr. Siegel presented results of research that showed a 10-millimeter gap reduced MERV 6 filters to less than a MERV 5, MERV 11 filters were reduced to MERV 8 and MERV 15 filters were reduced to MERV 8. The higher the efficiency of the filter (and the resistance) the more was lost in particle capture.

This illustrates the importance of proper gasketing of filters not only of the filter rack but also between filters. It also illustrates the importance of proper training of filter installers. The best training program for filter technicians is provided by the National Air Filtration Association and can be given by any Certified Air Filter Specialist (CAFS). Both Jim Rosenthal and Stevan Brown are Certified and can administer this training. Please call 817-261-3791 for details.

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