Assessing the impact of kitchen hoods and ventilation openings on indoor air quality post-cooking

Cooking is a major source of volatile compounds and pollutants, especially in Asian-style cooking. Exposure to these cooking-generated particulates has been linked to increased cancer risk, particularly in poorly ventilated environments. Removing these pollutants post-cooking is challenging, and without proper ventilation, residual pollutants can persist, harming health and potentially spreading indoors. Thus, studying post-cooking ventilation methods and air quality is crucial. This study investigates how exhaust hoods and natural ventilation openings remove cooking pollutants and enhance indoor air quality in a typical Taiwanese-style kitchen. Using a validated Computational Fluid Dynamics (CFD) model, various scenarios were simulated. These included continuous use of the exhaust hood after cooking, opening the front or back door, and using a transom to analyze the impact of different settings and climatic conditions on indoor air quality. The findings reveal that using both the front and back doors for ventilation creates strong convection, removing over 95 % of residual cooking pollutants in 10 min. In contrast, continued use of the exhaust hood after cooking may alter airflow direction but does not necessarily enhance pollutant removal. The concentration of residual particulate matter is primarily influenced by natural ventilation openings. Additionally, opening the back door and using a transom after cooking effectively removes pollutants compared to opening the door only, especially in winter. Proper ventilation disrupts the stratification effect of airflow, mixing fresh air with polluted air and inducing convection, resulting in significant pollutant removal.