Prediction of the temporal evolution of microparticle resuspension in ventilated duct during a fan start by a Monte Carlo model

Abstract

When a fan is turned on in a Heating Ventilating and Air Conditioning (HVAC) duct, it first exhibits a transient airflow period (acceleration regime) which is then followed by a constant airflow (steady state regime). Understanding particle resuspension in such realistic airflow scenario could prevent contamination of the surrounding environment and improve the indoor air quality. For this purpose, this work analyzes the temporal evolution of this phenomenon and relates it along with the instantaneous properties of the airflow pattern. To achieve this goal, a Monte Carlo (MC) numerical model is adapted in order to take into account the temporal airflow pattern during both accelerated and steady state regime. The numerical results obtained with this new version of the Monte Carlo model are compared with previous resuspension experiments performed in a ventilated duct using such airflow scenarios. A detailed analysis of the velocity profile and, above all, of its fluctuations is taken into account in the model. In light of the results obtained, it can be determined that this instantaneous aerodynamic information is essential for the model to provide realistic results in a non-steady airflow scenario.

Copyright © 2024 American Association for Aerosol Research

EDITOR:

• Andrea Ferro