Air filter classification is regulated by a series of very strict standard that
specifically define the features of the filters according to the relevant efficiency
class & use. the designer & the installation technician must know all these standards to
be able to propose the filter that best meets the project requirements. Below, are the
main standard used today with a series of table indicating the efficiency class of each
filter. Before starting, We want to remind you that the Air Filters considered by the
standards belong to three main groups:
Coarse/ Pre
Fine
Hepa
ULPA
EN 779 Standard
This Standard derives from revision of former EN 779. It Aims at determining the
arrestance of coarse filters with synthetic dust by using a gravimetric method & the
effiency of fine filters by using particle counter method. The standard has a double
classification system that uses letters & numbers G & F, respectively for coarse & fine
Filters, followed by number from 1 to 9.
EN 1822 Standard
The Most up-to date standard concerning HEPA & ULPA air is EN 1822. The new standard is
composed of 5 parts, each dealing with one specific subjects which is described in
details. It was stated that any single filtering medium has point of Maximum
penetration( or of lowest effiency) according to a specific particle Size.
TYPE of Filters
Class
Efficiency
Grade
EU Classification
MERV Rating
Course Filters (G-Category) Tested as per EN 779, ASHRAE 52.2
G1
EU-1
MERV-1
50% @ 50 MIC
G2
EU-2
MERV-2-4
80% @ 40 MIC
G3
EU-3
MERV-5-6
85% @ 20 MIC
G4
EU-4
MERV-7-8
90% @ 10 MIC
Medium Dust Filters Testes as per EN 779,ASHREA 52.2
F5
EU-5
MERV-9-10
95% @ 5 MIC
F6
EU-6
MERV-11-12
99% @ 5 MIC
Fine Dust Filters Tested As per EN 779, ASHREA 52.2
