Wearable Air Curtains as Advanced Personal Respiratory Protection

Samuel Sugarman, E.L. Pfeiffer, HEREK CLACK, Taza Aya, Inc.

     Abstract Number: 767
     Working Group: Aerosol Science of Infectious Diseases: Lessons and Open Questions on Models, Transmission and Mitigation

Abstract
Although face masks reduce the airborne spread of disease, the COVID-19 pandemic plainly demonstrated their numerous shortcomings as viewed by the general public, including breathing discomfort, diminished protection for children and those with facial hair, and interference with eating and drinking. Although face mask use has diminished along with the risk of severe COVID for many, millions of people remain at risk due to compromised immune response or comorbidities and face either continued social isolation or continued face mask use.

Air curtains are routinely used in buildings to maintain environmental separation between spaces. Taza Aya is developing a miniaturized, wearable air curtain - essentially mask-less personal respiratory protection - that avoids the limitations and discomfort of conventional face masks. To demonstrate the efficacy of wearable air curtains, aerosol challenge tests were conducted in a 2’ x 6’ x 2’ wind tunnel. A 3D-printed visor was mounted in the wind tunnel, custom designed with an array of air nozzles distributed along its brim. PM₁₀ aerosols were generated upstream of the mounted visor using either an ultrasonic nebulizer or a glycerol-based theatrical fog generator. Results show baseline PM₁₀ exclusion performance of > 95% for air curtain air flow rates up to 3 scfm, superior to most of the 11 common face coverings and face masks of a variety of materials reported by Pan et al. (2021). While N95/KN95 masks undoubtedly provide the highest level of protection, such protection is only assured with routine fit testing of an individual and their mask, an unworkable requirement for the general public. Wearable air curtains offer the potential for personal respiratory protection without the need for fit testing and without the inconveniences of traditional face masks.

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