Discussion on determination method of mass concentration calculation of outdoor fine particulate matter (PM2.5)

Based on the outdoor hourly mean mass concentration and daily mean mass concentration data in Beijing from January 1, 2014 to December 31, 2016, compares and analyses the impacts of the statistical calculation results using three common statistical calculation methods (annual non-guaranteed number of days, normal non-guaranteed number of days and annual non-guaranteed number of hours) on the design and selection calculation of the outdoor air filter. The results show that the annual non-guaranteed number of hours is suggested to determinate outdoor PM2.5 calculation mass concentration for the outdoor air filtration system, the annual non-guaranteed number of hours (during the day time 07:00—19:00) is suggested for the place where working mostly during the day, and the annual non-guaranteed number of hours (during the night time 20:00—06:00) is suggested for the place where high environment required and working all the day and night or during the night.