Relationship Between Indoor And Outdoor Of Fine Particulate Matter Concentration Levels In Residential Buildings

Fine particle is extremely harmful to human’s health for containing a lot of toxic and hazardous substance.Citizen stay in indoor environment for more than about 85% of their time,while the residence time accounts for more than 50% of it.Fine particulate in indoor air mainly from the outdoor,which mostly through the doors and windows to enter the room.In this paper,based on the numerical simulation and experimental research methods,the concentration relationship between indoor and outdoor fine particle was established,and the concentration levels of indoor fine particles were studied and predicted.Finally,the main research results are as following.(1)Through the establishment of indoor and outdoor fine particle concentration correlation model,the paper studied the fine particles through the doors and windows penetrating into the indoor environment.For residential buildings,since the more open time of the door,under the different window conditions(1/2 open windows,1/3 open windows,1/4 open windows,1/8 open windows and fully closed windows),the main research the effect of outdoor fine particle concentration on indoor fine particle concentration was studied.(2)The force of fine particlesresult study shows that the Drag,Gravity and Brownian force are the most important force on the moving particles in the air.The indoor velocity field and fine particle distribution under different window-open conditions were got by Fluent software.At the same time,by reading the simulating result of indoor center of the monitoring point and the concentration of fine particles in indoor and outdoor under different windows.We found that the concentration of residential indoor PM2.5 changes with the outdoor PM2.5,and the two trends were consistency.Besides,the size of the window is inversely proportional to the PM2.5 concentration between indoor and outdoor.Finally,the simulation results were verified by experiments,and the results are satisfactory.(3)In the experimental research,since some unknown problems existing between the pre-experiment and the formal experiment,so the correlation and regression analysis of the experimental results were carried out by SPSS19.0 and EXCEL2010.The results showed that the correlation was significant and the linear regression equation with high fitting degree was obtained.In addition,the settlement experiment of the indoor fine particles in both constant temperature and humidity environment,and the constant temperature changing humidity environment.Results showed the settling velocity of fine particles was proportional to the temperature and the humidity,and the influence of the humidity was greater than that of the temperature.Thus,by combining CFD simulation and experiment method to fitting formulae,along with the outdoor PM2.5 concentrations and the windows conditions,to predict the indoor PM2.5 concentration,which can help find the reasonable countermeasures and measures to improve the residential air quality.