CFD-Based Evaluation of Ventilation Strategies for Aerosol Transport in a Residential Home-Isolation Setting

The rapid spread of highly contagious respiratory diseases overwhelmed healthcare systems worldwide, making home isolation a critical strategy for managing infected individuals. However, inadequate ventilation in home isolation settings may increase the risk of transmission within households. This study aims to evaluate aerosol dispersion under various ventilation strategies using computational fluid dynamics (CFD) simulations. An Eulerian–Langrangian approach was applied to predict airflow and aerosol transport. The simulation results were validated with optical particle counter (OPC) measurements and RT-PCR analysis of surface samples for SARS-CoV-2 detection. Good agreement was obtained between the simulations and experimental data, with a relative error of less than 5%. A consistent inverse relationship between aerosol number concentration and RT-PCR cycle threshold (Ct) values was obtained. The ventilation strategy strongly affects aerosol distribution. Inside the quarantine room, opening the window reduced aerosol concentration by approximately 25% compared to air-conditioning turn on. However, aerosol concentration near leakage pathways increased by up to 4.9 times when the window was open, indicating greater aerosol escape from the room. In multi-room scenarios, window opening increased aerosol concentrations in the corridor by 2.3–2.7 times and in interconnection areas by up to 2.1 times. Installing exhaust fans significantly improved aerosol control. External exhaust fans reduced concentrations by approximately 13–29% in the room, 24–38% in the corridor, and 30–62% in interconnection areas. Internal exhaust fans provided more effective mitigation, reducing aerosol concentrations in adjacent spaces by over 97–100%, and substantially reducing aerosol leakage. Increasing the ventilation rate further enhanced aerosol removal. Raising the ventilation rate from 6 to 12 air changes per hour (ACH) reduced aerosol concentrations in adjacent spaces by more than 99%, while reductions inside the room were moderate. A suitable ventilation rate was 10 ACH, achieving over 98% reduction in aerosol transmission while maintaining practical conditions for residential applications. These results indicate that aerosol containment is governed not by air exchange rate alone, but also by the airflow pathway and the relative configuration of the aerosol source, ventilation openings, and exhaust.