A measure of the ability of filter media to separate out particles in the airstream. There are many different standards and methods to measure efficiency, making it almost impossible to compare the e [..]

This term indicates the percentage of particles that a filter captures as air moves through it. Filtration efficiency is typically stated with regard to a specific particle size. For example, a HEPA filter retains 99.97% (filtration efficiency) of particles 0.3 microns (particle size) or larger. In order to make an informed decision about how well [..]