HEPA Efficiency is much more than simply using HEPA grade filters... The HEPA filter needs to be properly sealed to provide HEPA results! Take a look at what Amaircare does for every filter to ensure it performs to HEPA standards.

HEPA Efficiency: Removal of 99.97% of particles at 0.3 microns in size.
So out of 1,000,000 (0.3 micron sized) particles, a true HEPA filter would capture all but 300.

Ambient Air: To test for 99.97% efficiency, a reading must first be done to test the number of 0.3 micron sized particles in the air before filtration.

A MetOne laser particle counter is used. It is calibrated to count 0.3 micron sized particles per cubic foot of air.

Tested Ambient Air: 613,300 particles / cubic foot

HEPA efficiency in this case, is a filtered result of 184 particles / cubic foot or less..

Filtered Air: The particle counter is then arranged so that it is taking in 100% of the outflow air from the HEPA filter. The results show how many 0.3 micron particles escape the HEPA filtration process.

Tested Filtered Air: 100 particles / cubic foot

Tested Efficiency: 99.98%