Maddocks Group

Industrial Filter Division


(905) 549-9626

663 Woodward Avenue
Hamilton, Ontario, Canada L8H 6P3

MERV Ratings

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The acronym MERV stands for "Minimum Efficiency Reporting Value". The MERV rating is the standard method for comparing the efficiency of an air filter. The higher the MERV rating, the better the filter is at removing particles from the air down to sub micron size.

100% Cellulose 10 50-60% 1-3
80 Cellulose / 20 Polyester 11 65-80% 1-3
Spunbond Polyester 12 80+% 1-3
80 Cellulose / 20 Polyester with Nanofiber 15 85-95% .3-1
Spunbond Polyester with PTFE Membrane 16 99.5% .3-1
HEPA Media 17 99.97% .3
ULPA Media 19 99.99% .3

*It should be noted that the ASHRAE 52.2 test procedure returns the MINIMUM efficiency value for the tested filter. In actual use, once the filters have been coated with particulate, the filter efficiency would be much higher than that reported through the test.

MERV Chart

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