Experimental Investigation on Indoor/Outdoor PM2.5 Concentrations of an Office Building Located in Guangzhou

Abstract

The Pearl River Delta (PRD) is one of the areas that are facing a serious fine particulate matter (PM2.5) pollution in China. In order to grasp the variation law of PM2.5 concentrations in the atmospheric environment and its impact on the indoor environment, this research has taken a certain naturally ventilated office building as the monitoring object to constantly monitor its mass concentration of indoor and outdoor PM2.5 and meteorological parameters from February to July 2014 and from December 2014 to January 2015 in Guangzhou. During the test period, the external windows and mechanical ventilation system stayed closed and there were no other indoor pollution sources. The survey results showed: (1) among all diurnal variations, the diurnal variation in hourly average mass concentrations for outdoor PM2.5 showed that the night experienced greater variation than the day; in terms of seasonal variation, Spring experienced the most severe outdoor PM2.5 mass pollution (115μg/m3), followed by Winter (95μg/m3); (2) the indoor PM2.5 mass concentrations were highly correlated with that outdoor, meanwhile the indoor/outdoor PM2.5 mass concentrations ratios (I/O ratios) were in a broad range; (3) both outdoor PM2.5 mass concentrations and infiltration factors were significantly correlated with meteorological parameters (temperature, wind speed and relative humidity); (4) compared with the related research conducted on Beijing, PM2.5 concentrations and infiltration factors in both the two regions were affected by wind speed and relative humidity, but the impact of temperature on outdoor PM2.5 concentrations was not discernible in Beijing. The research results can serve as a reference for analyzing the influence rule of outdoor PM2.5 situation to the indoor environment in the Pearl River Delta region and its control technology.