Calculation on Pollution Load of Air Purifier

Abstract

The pollution load of air purifier mainly means the concentration of particles invaded into the room, i.e., the PM2.5 concentration. Several years ago, there were days with dust storms in Beijing. The sky was gloomy and gray. But there was no feeling of wind. When people went back home after one-day out, a layer of something could be seen on the table. The floor also seemed to be a little gloomy. Since the double layered window was used, how did the pollutant come indoors without the help of the wind?