Comparison of removal effectiveness of mixed versus displacement ventilation during vacuuming session

Abstract

In indoor environments, floor surfaces are sinks of particles that might re-suspend in air. If not removed by the ventilation configuration, particles carrying bacteria and viruses constitute a threat for occupant’s health. Selecting a proper ventilation system with convenient design parameters plays an important role in particle removal from the occupied space. In this work, a typical office space was considered with the option of varying the ventilation configuration by considering a mixing ventilation (MV) system, displacement ventilation (DV) system, and reversed displacement ventilation (RDV) system. The effectiveness of these systems in removing resuspended particles from the indoor space during vacuuming sessions was studied. For this reason, a transient 3D computational fluid dynamics (CFD) model was developed and was validated experimentally in a climatic chamber equipped with both MV and DV systems. Good agreement was obtained between measured and predicted values of particles’ concentration with low relative error in the order of 10 %. The parametric study conducted showed that the reversed DV configuration insured the best particle removal performance by resulting in an effective suction effect at the floor level. The worst performance was provided by the conventional DV system due to the upward DV airflow transporting the resuspended particles from the floor levels to the upper breathing levels spreading contaminants. From here the RDV configuration was suggested for operation of ventilation system during vacuuming session to enhance particle removal. © 2020, European Association for the Development of Renewable Energy, Environment and Power Quality (EA4EPQ). All rights reserved.