Research on the dynamic characteristics of indoor and outdoor environmental quality of office buildings based on long-term online monitoring of Internet of Things

In order to recognize the dynamic characteristics of indoor and outdoor environmental quality of office buildings, this paper utilizes Internet of Things technology to build an indoor and outdoor environmental quality monitoring system to continuously monitor an office building in Xiamen, Fujian Province for one year, and analyzes the pollution and variation characteristics of temperature, humidity, illumination, formaldehyde, TVOC, CO2 and PM2.5 in different floors of 6th, 9th, and 15th at different time scales. The results show that：① for the daily variation, the indoor and outdoor temperature and humidity of offices at different floors show a trend of first increasing and then decreasing. In contrast, illumination shows a trend of first decreasing and then increasing. PM2.5 shows a gradual downward trend. The concentrations of formaldehyde, TVOC and CO2 indoor and outdoor offices at different floor heights gradually decrease with the increase of floor height. ② For the seasonal variation, the trend of indoor and outdoor temperature of offices with different floors is ranked as follows：summer > autumn > spring > winter. The indoor humidity presents the rule of summer > spring > autumn > winter, while the rank of indoor PM2.5 is winter > spring > autumn > summer. However, the outdoor humidity, outdoor PM2.5 and indoor and outdoor illumination, formaldehyde TVOC and CO2 have little relationship with seasonal alternation. ③The indoor and outdoor environmental quality of offices with different floor heights showed no significant difference on weekdays and weekends. ④For the diurnal variation, the indoor and outdoor temperature, humidity, illumination, formaldehyde, TVOC and CO2 of offices at different floors have obvious trends, except PM2.5. The concentrations of formaldehyde, TVOC and CO2 decrease with the increase of floor height, and there is a lag effect on the variation trend of indoor and outdoor environmental quality factors. © 2022 Science Press. All rights reserved.