Comparison test of filtration performance of class F7 air filters

Performs experiments according to EN 779:2012 and real-time monitoring test method, and compares two bag-type air filters sold as class F7. The result indicates that their real efficiencies are different greatly even for the same class label, and the impact of electrostatic effect is great. Suggests that a new regulation should be added in new version of the standard in the future: the discharging procedure must be carried out before dust loading test.