Ventilation indices for evaluation of airborne infection risk control performance of air distribution. (15th August 2022)

• Record Type: Journal Article
• Authors: Lu, Yalin; Niu, Dun; Zhang, Sheng; Chang, Han; Lin, Zhang
• Is Part Of: Building and environment. Volume 222(2022)
• Publication Date: 2022-08-15
• Subjects: Airborne infection risk -- Air utilization effectiveness -- Contaminant dispersion index -- Age of air -- Air change effectiveness -- Contaminant removal effectiveness; ACE Air change effectiveness -- AoA Age of air -- AUE Air utilization effectiveness -- CDI Contaminant dispersion index -- CRE Contaminant removal effectiveness -- DV Displacement ventilation -- DWV Downward ventilation -- MAE Mean absolute error -- MV Mixing ventilation -- SV Stratum ventilation; Buildings -- Environmental engineering -- Periodicals; Building -- Research -- Periodicals; Constructions -- Technique de l'environnement -- Périodiques; Electronic journals; 696
• DOI: 10.1016/j.buildenv.2022.109440
• Languages: English
• ISSNs: 0360-1323

Abstract

Abstract: Air distribution is an effective engineering measure to fight against respiratory infectious diseases like COVID-19. Ventilation indices are widely used to indicate the airborne infection risk of respiratory infectious diseases due to the practical convenience. This study investigates the relationships between the ventilation indices and airborne infection risk to suggest the proper ventilation indices for the evaluation of airborne infection risk control performance of air distribution. Besides the commonly used ventilation indices of the age of air ( AoA ), air change effectiveness ( ACE ), and contaminant removal effectiveness ( CRE ), this study introduces two ventilation indices, i.e ., the air utilization effectiveness ( AUE ) and contaminant dispersion index ( CDI ). CFD simulations of a hospital ward and a classroom served by different air distributions, including mixing ventilation, displacement ventilation, stratum ventilation and downward ventilation, are validated to calculate the ventilation indices and airborne infection risk. A three-step correlation analysis based on Spearman's rank correlation coefficient, Pearson correlation coefficient, and goodness of fit and a min-max normalization-based error analysis are developed to qualitatively and quantitatively test the validity of ventilation indices respectively. The results recommend the integrated index of AUE and CDI to indicate the overall airborne infection risk, and CDI to indicate the local airborne infection risk respectively regardless of the effects of air distribution, supply airflow rate, infectivity intensity, room configuration and occupant distribution. This study contributes to airborne transmission control of infectious respiratory diseases with air distribution. Highlights: Relationships between ventilation indices and airborne infection risk are tested qualitatively and quantitatively. Different air distributions, ventilation rates, infectivity intensities, room configurations, and occupants are considered. Integrated index of AUE and CDI robustly indicates overall airborne infection risk control performance of air distribution. CDI robustly indicates local airborne infection risk control performance of air distribution.