Experimental analysis of the effect of temperature and relative humidity on indoor VOC emission with the high occupancy rate

Volatile organic compounds (VOCs) are one of the most important indoor air pollutants. Balancing the source intensity of VOCs and ventilation strategies is an important way to obtain an acceptable indoor environment quality. The human body emits a wide range of chemicals, including CO2 and TVOC. To examine the impact of temperature and relative humidity on human emission rates of VOCs, we conducted an across-subject experiment in December 2021. The experiments were taken on three consecutive days on groups of 14 people under different temperatures and relative humidity. A counterbalanced study in a controlled chamber which replicated an office environment involving 14 students. In groups of seven, participants engaged in 30 minutes each of cognitive tasks under different environmental conditions. In this study, the per capita VOC emission rate ranged from 0.15 to 0.41μg/s. Measured biomarkers indicating the per capita VOC emission rate increased significantly when people felt warm (p<0.05) both at 50% and 70% relative humidity, when the thermal sensation of the personnel was the same: the higher the relative humidity, the higher the per capita VOC emission rate. This study explored the effects of temperature and humidity on indoor per capita VOC emissions under actual personnel conditions, intending to provide a corresponding reference for indoor air quality control. These results implied the possibility of considering temperature and relative humidity in determining indoor per capita VOC emission rates. They also presented the possibility of monitoring indicators of cognitive tasks of occupants through measurement of air quality.