The Purified Crosswind Air Barrier
Synopsis
The Centers for Disease Control declared SARS-CoV-2 an airborne pathogen. That means infectious aerosols smaller than 5 microns in diameter are now the dominant transmission mode in healthcare centers where employees wear masks while residents and patients do not. Surgical masks are effective at reducing aerosols from workers; however, approximately 10% of aerosolized infectious particles are not blocked during speech and normal breathing exposing unmasked residents and patients to infection in a close interaction with an infected worker. In this city during October and November 2020, three hospitals and sixty-one long term care centers were infected, some re-infected after a summer green period, in a resurgent wave of the epidemic. The solution presented here was specifically engineered to mitigate infection in the interaction zone where a masked worker attends to an unmasked resident or patient by providing an active physical barrier of purified air between both individuals. This solution deflects and then filters infectious aerosols, instantaneously reducing the existing infection probability by a predicted value of approximately 99.93% during a 10-minute interaction in a typical residence room by an infected worker or by an infected patient in a hospital room. A distributed version of this solution should be immediately considered even for modern hospitals despite HEPA air quality and fresh air in their HVAC systems. Variations of this concept can be applied to any indoor space where two or more individuals interact. If every indoor interaction zone obtains a solution based on this concept, there is a good chance the epidemic can be brought under sufficient control to have commerce reopened. It would also relieve distress in citizenry to know there is an external technological solution that does not entirely rely on their behavior. Moreover, in future respiratory epidemics, preinstalled, this solution can always be on standby and brought into immediate mitigation service without having to wait for vaccines. Commercial HEPA air purifiers can be installed in classrooms, however, caution should be exercised with guidance demonstrated here to ensure all persons who interact can sense sufficient aerosol-deflecting airflow on their faces at all times. Without feeling airflow, a commercial air purifier placed ad-hoc in a classroom would be much less effective.