Prediction of the concentration and diameter distribution of indoor suspended particulate matter

Purpose - The purpose of this paper is to establish mass balance model and predict the concentration and diameter distribution of indoor suspended particulate matters (SPM). Design/methodology/approach - Taking the small offices and residences for a research objective, this paper analyzes the major factors to affect the concentration and diameter distribution of indoor SPM, founds the deposition ratio model, the penetration factor model and the mass balance model to predict the concentration and diameter distribution of indoor SPM. According to the real-time measuring data, the feature of building defence structure and the concentration and diameter distribution of outdoor SPM, the deposition model, the penetration model and indoor air capacity are used as input parameter of the mass balance model. Findings - The size of defence in natural ventilation, the pressure difference of both sides and the friction velocity have less influence on the concentration and diameter distribution of indoor SPM, but the concentration and diameter distribution of outdoor SPM mainly affects that of indoor SPM. Indoor particle concentration change with outdoor particle concentration, and less than later because of indoor particle deposition. The prediction results are basically in agreement with the measuring data. Research limitations/implications - Real-time and accuracy of measuring data of outdoor SPM are the main limitations which the prediction model are simulated. Practical implications - The prediction results can provide scientific theory basis for making environmental standards of particulate matter and the control of indoor air quality. Originality/value - A new method to predict the concentration and diameter distribution of indoor SPM.