ISO 29463 originates from EN1822, which defines EPA, HEPA and ULPA filters commonly used in industry. While ISO 29463 maintains the classification of EPA, HEPA and ULPA.But replace E10-E12, H13-H14 and U15-U17 with the following 13 filter levels. The ISO 29463 can't replace EN 1822, EN 1822 will continue to be valid.
In modern air filtration applications, users are increasingly concerned with how well filters remove particles in the PM2.5 and PM10 size ranges. ISO 16890 is now the leading international standard for evaluating air filter performance for general ventilation. This article provides a clear explanation of how ISO 16890 defines and measures ePM1, ePM2.5, ePM10, and Coarse filtration efficiencies, as well as key topics such as aerosol types, particle size classification, data processing, and equipment design requirements.
It is generally believed that as airflow increases, face velocity increases, and filtration efficiency decreases. In other words, lower airflow (lower velocity) should lead to higher filtration efficiency. However, in actual testing—such as at 500 m³/h—the opposite is sometimes observed: efficiency decreases when airflow is reduced. This article aims to analyze the underlying reasons. Notably, this phenomenon has also been observed by experienced professionals in the filtration industry, and we share our findings and discussion here.
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