Penetration of outdoor fine particulate matter (PM2.5) through building envelope and passive control methods

In order to explore the causes and influencing factors of the outdoor fine particulate matter (PM2.5) entering indoor environment through the cracks of building envelope, as well as to propose passive control methods based on the conception of source control, analyses the relationship between indoor and outdoor PM2.5 concentrations and the barrier effect of external window air tightness on outdoor PM2.5 by the approach of actual measurement. Based on the model of outdoor PM2.5 penetration through building envelope cracks, analyses the influencing factors of PM2.5 penetration. Puts forward some passive control methods based on the results of actual measurement and theoretical analysis. The results show that indoor and outdoor PM2.5 concentrations are relevant and the windows with better air tightness have a stronger barrier effect on preventing outdoor PM2.5, and that the penetration of outdoor PM2.5 through building envelope is influenced by air change rates. Therefore, for residential buildings and the buildings without continuous positive pressure protection, some passive control methods should be taken to reduce the penetration of outdoor PM2.5 into indoor environment, including choosing windows with better air tightness, ensuring the product quality and the installation quality of sealing strips of external windows, enhancing the sealing of reserved holes in building walls and maintaining periodically.