Why we measure only 0.5 and 5 micron NVPC in HVAC validation.
Most commonly bacteria size is in between 0.5 to 5.0 micron and bacteria less likely attach to non viable particle size smaller than 0.5 micron so particle size smaller than 0.5 is not critical issue.particle size greater than 5.0 micron is not good carrier for bacteria because it settles down easily due to heavy weight.
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