MERV

Filter Media, Relative Air-Cleaning Abilities:

media

MERV *

3 - 10µ

1 - 3µ

0.3 - 1µ

odor removal with Carbonized Basal Planes **

glass

1

< 20

 

 

 

 

2

< 20

 

 

 

panel / pleated

3

< 20

 

 

complete

 

4

< 20

 

 

 

 

5

20 - 35

 

 

 

 

6

35 - 50

 

 

 

 

7

50 - 70

 

 

 

electret, 1 ply

8

> 70

 

 

complete

 

9

> 85

< 50

 

 

 

10

> 85

50 - 65

 

 

 

11

> 85

65 - 80

 

 

electret, 2 plies

12

> 90

> 80

 

complete

 

13

> 90

> 90

< 75

 

 

14

> 90

> 90

75 - 85

 

 

15

> 90

> 90

85 - 95

 

 

16

> 95

> 90

> 95

 

* MERV (Minimum Efficiency Reporting Value) - a number from a test method designed by ASHRAE
(American Society of Heating, Refrigerating & Air Conditioning Engineers) to help compare particulate filter efficiencies.

  • Chemist’s Note:
    I welcome the improved particulate standards, however it is well to remember that most indoor air problems are caused by unfilterable molecules, not particles

    molecules are roughly 0.001 to 0.01 microns
    viruses are approximately 0.2 microns
    bacteria range from 0.3 to 4 microns
    allergens such as pollen and fungal spores are at least 3 to 20 microns
    plant or animal cells are 10 to 30 microns
    human hair is approximately 80 microns

Richard Kunz, chemist
719 635-1325