Reduced personal exposure to airborne cross-infection using wearable exhaust ventilation

Abstract

This study aimed to explore an alternative solution for protection against cross-infection. Exposure reduction to exhaled airborne contaminants by wearing an exhaust nozzle was studied. Experiments were performed in a full-scale test room (64.8 m3) equipped with a small section of a stadium tribune with six seats. Two breathing thermal manikins and four heated dummies were placed on the tribune. The manikins were equipped with artificial lungs simulating a realistic breathing cycle and respiratory flow. One of the breathing manikins was used to mimic a sick person having an infectious respiratory disease. The exhaled air of the “infecting person” was mixed with tracer gas to imitate pathogens. Four types of air exhaust nozzles were studied for their efficiency to reduce exposure to exhaled contaminants. The nozzle was positioned in front of the mouth of the infecting person. The test room was ventilated with mixing background ventilation. The use of the exhaust nozzle resulted in cleaner air in the room and at the breathing zone of the simulated occupants compared to only using dilution by the background ventilation. The novel device has the potential to capture exhaled air and reduce airborne cross-infection in densely occupied sitting areas.