Effect of air outlet location on dust spatial distribution and ventilation effectiveness in a full-scale experimental room

摘要

A clear understanding of airborne particulate spatial distribution can provide important information for improvement of ventilation system design and control strategies. In this study, the dust mass spatial distributions in three different ventilation systems were measured using a multi-point sampler in a full-scale mechanically ventilated laboratory room under controlled conditions. The experimental results show that the particle mass spatial concentrations vary widely as a result of ventilation.Increasing the ventilation rate reduced the overall mean particle concentration with the same ventilation system. At the same ventilation rate, the ventilation effectiveness varied widely with different ventilation systems. The experimental results alsoshow that the air outlet location had a substantial effect on the dust spatial distribution and the overall dust mass concentration. Ventilation system design was critical to the dust control in a mechanically ventilated airspace. Positioning the air outlet at the dustiest location can substantially improve dust removal effectiveness. The ventilation effectiveness factor was used to quantitatively describe the effectiveness of ventilation system for removal of contaminant in a ventilated airspace.