Study on Distribution and Deposition of House Dust by Different Ventilation Systems in a Full-scale Residential Room

Abstract

House dust contamination has recently become an important issue in the residential indoor environment. This study evaluated ventilation systems for removing house dust efficiently in a full-scale residential room. Experiments and simulations were performed to investigate diffusion and deposition of house dust by different ventilation systems. Riboflavin particles were used as the house dust. Two kinds of ventilation systems were considered, namely ceiling exhaust and slit exhaust. In the experiments, whether high air change rate (2.5 ac/h) or low air change rate (0.75 ac/h), the amount of house dust in the ceiling exhaust was a little larger than that of the slit exhaust after house dust decreased to the same level as background. Diffusion fields were investigated by CFD simulations, the house dust with diameter of 0.5 ~ 3.0 μm in the experimental data and calculated values showed good agreement. From the data, it is shown that the removal efficiency of the slit exhaust was 5.3% and 11.1% higher than the ceiling exhaust after two hours of operation at 0.75 ac/h and 2.5 ac/h, respectively. Based on the results of this study, it is concluded that the house dust in the full-scale residential room using a slit exhaust ventilation system is lower than ceiling exhaust at both high and low air change rates.