The EN779:2002 has remained unchanged for ten years and was updated in 2012. Intensive discussions within the European technical associations finally led to a substantial extension of the test norm. For the very first time a minimum efficiency for discharged filter medium was defined and became a compulsory part of the new test procedure. Additionally, it was possible to compare energy consumption on the basis of EUROVENT 4/21.
Maximum allowed prssure drop [Pa]
Average Filtration [%]
Mean degree of efficiency for particle size 0.4 μm [%]
Minimum degree of efficiency for particle size 0.4 μm [%]
This DIN EN779:2012 was globally replaced by the ISO 16890 in 2017, which revolutionizes the assessment and classification of air filters. Although the ISO 16890 is widely welcomed by the scientific community , at the same time it imposes great challenges to the test labs, the filter manufacturers as well as the filter trading companies.
New dust and new classes
The ISO 16890 will replace the well known filter classifications M5 -F9 by the introduction of ePM classes. The ePM classes no longer measure the filter efficiency of one single particle size. The new filter classes contain the definition of filtration efficiency of various particle ranges (ePM1 0.3 – 1 µm, ePM2.5 0.3 – 2.5 µm, ePM 10 0.3µm - 10µm).
The test bench is upgraded
The measurement is still perfomed with DEHS up to a particle size of 1 µm. In areas of particle sizes > 1 µm, KCl is used as test aerosol.
The discharging method, which became compulsory in 2012 as part of the main body of the norm called DIN EN 779, contains the discharge of small filter media flat sheet samples. Up to now these local minimum efficiencies were considered sufficient to induce conclusions for a fully assembled filter unit. The introduction of the ISO 16890 will make it necessary to discharge entire filter units.
Harmonized type of testing dust according to 1210 3 PT1. A2 Fine
Changed to consider recommendations of WHO on the limit values for fine-duct pollution
Testing in conditions of complete discharge of media
Better tailoring of HVAC equipment to requirements in design and layout stage