Reduced infection risks: A tailored ventilation concept for passenger trains decreasing the dispersion of exhaled aerosol particles

Abstract

We report on an experimental study of state-of-the-art “classical” ventilation systems and a novel headrest-integrated ventilation system for passenger compartments. The main objective of the novel ventilation system is to reduce the spread of exhaled particles, often referred to simply as aerosols, in densely occupied spaces such as passenger train compartments or aircraft cabins. The concepts were evaluated in terms of many different parameters such as contaminant removal efficiency, the number of seats above a certain threshold or the mean particle concentration in the breathing zone of the passengers. It was found that the different state-of-the-art concepts are of similar quality in terms of aerosol dispersion. While some concepts are marginally better for single parameter, they are slightly worse in others. Overall, the variance of the evaluation parameter between the different state-of-the-art concepts is rather small. A generic prototype was designed, 3D-printed and tested for different operating configurations in a generic train laboratory. Regarding the new concept, the results demonstrated the positive effect of the active system in reducing the average particle load throughout the compartment as well as the peak concentration on the neighbouring seat. The best results were found for the combined blowing-suction configuration at high flow rates, reducing the peak load by more than 40% and the mean load by approx. 50%, compared to the standard ceiling-based ventilation case without in-seat ventilation system.