ASHRAE Standard 52.2-1999ASHRAE 52.1ENEN779:2012EN 1822

Minimum Eff Reporting Value

Composite Average Particle Size Efficiency % in Size Range, μm

Average Arrestance

Average Dust Spot Efficiency

Filter Class

Av. Arrestance of Syn. Dust

Av. Eff at 0.4 μm

Min Eff. at 0.4 μm

Average Eff at MPPS μm

 Range 1Range 2Range 3

NB. This standard is obsolete and here for reference only. Performances are not equivalent to ASHREA 52:2 or EN779.

 Test Final DP 250PaTest Final Dp 450Pa 
( MERV )0.30 – 1.01.0 – 3.03.0 – 10.0%% %%%%
1n/an/aE3<20Aavg<65<20G150≤Am≤65   
2n/an/aE3<20Aavg<65<20G265≤Am≤80   
3n/an/aE3<20Aavg<70<20 
4n/an/aE3<20Aavg<75<20 
5n/an/aE3≥208020G380≤Am≤90   
6n/an/aE3≥358520-25 
7n/an/aE3≥509025-30G490Am≤   
8n/an/aE3≥709230-35 
9n/an/aE3≥859540-45M5 40≤Em≤60  
10n/aE2≥50E3≥859250-55 
11n/aE2≥65E3≥859760-65M6 60≤Em≤80  
12n/aE2≥80E3≥909870-75 
13n/aE2≥90E2≥909880-85F7  80≤Em≤9035 
14n/aE2≥90E2≥909990-95F8  90≤Em≤9555 
15n/aE2≥90E2≥909995F9  95≤Em70 
16n/aE2≥95E2≥9510099E10   <85
N/AN/AN/AN/AN/AN/AE11   <95
E12   <99.5
H13   <99.95
H14   <99.995
U15   <99.9995
U16   <99.99995
U17   <99.999995

Note: The final MERV value is the highest MERV where the filter data meets all requirements of that MERV.