Abstract View
Insights into the Strategies of Reducing the Aerosol Particle Concentration in Indoor Environments Using Mobile Air Purifiers - Experimental and Numerical Analyzes
ADRIAN TOBISCH, Lukas Springsklee, Lisa-Franziska Schaefer, Nico Sussmann, Martin Lehmann, Raoul Zoellner, Jennifer Niessner, Heilbronn University of Applied Sciences
Abstract Number: 309
Working Group: Aerosol Exposure
Abstract
Aerosols are generally recognized as one of the main routes of transmission of COVID-19. In order to reduce the risk of infection indoors, mobile air purifiers are used. We focus on the effects of a filtrating air purifier. Specifically, we report results of ongoing work applying a sensor network of 12 sensors (PM 1) measuring and simulating particle concentration at head height and taking thermal effects into account.
In an auditorium, simple-made setup of “thermal dummies” were placed at some seats to simulate the effect of persons being in the room. In this work, we investigate the transport of aerosol particles from a dummy equipped with an aerosol generator (“infected dummy”) to receiving thermal dummies. Experimental and numerical methods are used to investigate how the risk of infection suggested by the particle concentration in an exemplary lecture hall can be reduced by a clever choice of the location and orientation of the air purifier. For analyses, we use optical particle counters and a sensor network to monitor the particle concentration and particle size spectrum with high spatial resolution. A computational fluid dynamics (CFD) model is set up and validated based on the measurement data.
At the recommended air exchange rate of 5.1 /h, the cumulated PM 1 mass at head level was reduced by 75 %, independently of the location of the infected dummy, compared to the “no air purifier” case. It turns out that a corner installation of the air purifier with a blow out against the wall may be particularly advantageous. In this best case, the particle mass at head height throughout the lecture hall was reduced by approximately 13 % points more than compared to the worst case location and orientation. We will discuss further results of spatially resolved particle measurements and simulations.