AirPurifier Technology Comparison Video
I.e. at 0:57 HEPA filters in PM2.5 rating will be definitely VERY excellent. Even finedustfilters falling into ISO 16890 range would be excellent to remove PM2.5. Typical bacteria can't pass a HEPA Filter conforming EN1822 due to the fact that their particle size is far greater than the most penetrating particle size which is chosen as performance criteria for HEPA filters. The vid. is not correct and missleading at that There's no information at all about activated carbons removal capability of VOC's, O3, NHx etc.but would have been required to have an objective review of the air purifiers spec.