In the past few years, a lot of effort has been spent in the removal of particles from outside air for indoor environments. The measurement of particles, in terms of PM2.5 and PM10.0 for outdoor air quality, has been implemented step by step into filtration standards like ISO 16890. Moreover, the importance of indoor air has also gotten significant public interest due to the COVID-19 pandemic. Since there is a continuous decrease of particulate matter in ambient air, the focus of filtration has increasingly shifted to molecular filtration, i.e. the contemporaneous separation of particles and harmful gases (e.g.: ozone O₃, nitrogen oxides NO_X, sulphur dioxide SO₂, toluene C₇H₈, ammonia, acetaldehyde C₂H₄O). Thus, multi-functional filters (e.g. C-VAC) have been developed and are already used in several applications.

In the area of cabin air filter testing according to ISO 11155-2, molecular filtration has already been addressed for several years. Nowadays, standardised test systems (like PAF 112/113, Topas GmbH, Germany) are well distributed all around the world (Bucevschi et al 2021). With these test systems, either filter media, activated carbon bulk or filter elements for cabin air, can be tested simultaneously with several of the above-mentioned gases. During development focus was given to the secure handling of these gases due to high occupational safety standards, as well as in order to avoid cross-contaminations and to minimize gas interactions.

All these considerations regarding gas handling are now currently being transferred from cabin air filtration into general ventilation air filtration in accordance with ISO 10121. Utilizing the well-known ALF 114 system for general ventilation air filter ISO 16890, (Todea et al. 2020) the measurement of particulate filtration has been conducted worldwide for several years now. This knowledge, combined with the knowledge of cabin air filtration, is now leading to the first commercial test system (GAF 114, Topas GmbH), which will enable molecular filtration testing on large filters up to 610x610 mm.

This presentation will show the technical details of the new test system, as well as the first results for molecular filtration.