Converting Passive Filtration Media into Active Air Biofiltration Surfaces for Airborne Viral Reduction

Conventional air filtration relies on passive mechanical capture without pathogen inactivation, where viral reduction must be balanced with airflow and energy performance. We developed an Ablative Polymer Coated (APC) filtration system that converts passive filters into active pathogen-reducing surfaces while maintaining low airflow resistance. Unlike conventional approaches requiring denser, higher-resistance media, this strategy enhances biological performance at the filter surface without equivalent aerodynamic penalties. The coating incorporates benzalkonium chloride within a polyvinyl acetate/acrylate matrix for controlled ablative exposure. Performance was evaluated using transmission electron microscopy (TEM), aerosol challenge testing, and HVAC-scale filtration. Ablative exposure caused progressive structural disruption of MS2 bacteriophage, the SARS-CoV-2 simulant. In aerosol challenge testing, coated media achieved up to 99.997% viral filtration efficiency under respiratory airflow conditions. In HVAC (Heating, Ventilation, and Air Conditioning)-scale testing, coated filters achieved >85% viral filtration efficiency with minimal pressure-drop increase. Computational fluid dynamics modeling confirmed uniform airflow distribution without significant turbulence generation. Energy analysis suggested coated filters may reduce energy demand relative to conventional higher-resistance configurations while improving biological performance. These findings support ablative polymer-coated media as a strategy for reducing airborne viral burden without aerodynamic penalties of higher-efficiency passive filtration, suggesting an approach that complements rather than depends solely on tighter filter design.