Effect of ventilation strategies for removing indoor house dust: An experimental and simulation study

Abstract

House dust includes the mold spores or corpses and feces of the mite, among other things, which would cause allergies, asthma, and unspecific hypersensitivities. The possibility of having an allergic reaction to house dust is particularly high for children. In this study, experiments and simulations were performed to study the flow and diffusion fields affected by different location and shape of outlets. Two kinds of ventilation strategies were considered, i.e., ceiling exhaust and floor-level slit exhaust. In the experiments, for the two cases, the characteristics of airflow within the whole room are generally similar except for the airflow close to the outlet. Riboflavin particles were used as the house dust; the amount of particles in the ceiling exhaust was a little larger than that of the slit exhausted after particles decreased to the same level as the background. Flow and diffusion fields were investigated by computational fluid dynamics (CFD) simulations. The characteristics of airflow are similar for both experimental and simulation results. The particles with a diameter of 0.5–3.0 μm in the experimental data and calculated values showed good agreement. It was concluded that floor-level slit exhaust ventilation strategy produced less house dust in the whole room than the ceiling exhaust did.

Acknowledgments

This research is supported by the Ministry of Land, Infrastructure, Transport and Tourism of Japan and the Fundamental Research Funds for the Central Universities of China, as a part of a technology guide related to a residential construction development promotion business program on “Technological development on reduction of health problems caused by house dust” and Inter Central corporation consignment research. The authors would like to express sincere appreciation to all the people related to this research.

Yang Lu, PhD, is Lecturer. Hiroshi Yoshino, PhD, Fellow ASHRAE, is Professor. Rie Takaki, PhD, is Assistant Professor. Genta Kurihara is Graduate Student.