The Synergistic Effect of PM 2.5 and CO 2 Concentrations on Occupant Satisfaction and Work Productivity in a Meeting Room

High indoor air quality is crucial for the health of human beings. The purpose of this work is to analyze the synergistic effect of particulate matter 2.5 (PM 2.5 ) and carbon dioxide (CO 2 ) concentration on occupant satisfaction and work productivity. This study carried out a real-scale experiments in a meeting room with exposures of up to one hour. Indoor environment parameters, including air temperature, relative humidity, illuminance, and noise level, were controlled at a reasonable level. Twenty-nine young participants were participated in the experiments. Four mental tasks were conducted to quantitatively evaluate the work productivity of occupants and a questionnaire was used to access participants’ satisfaction. The Spearman correlation analysis and two-way analysis of variance were applied. It was found that the overall performance declined by 1% for every 10 μg/m 3 increase in PM 2.5 concentration. Moreover, for every 10% increase in dissatisfaction with air quality, productivity performance decreased by 1.1% or more. It should be noted that a high CO 2 concentration (800 ppm) has a stronger negative effect on occupant satisfaction towards air quality than PM 2.5 concentration in a non-ventilated room. In order to obtain optimal occupant satisfaction and work productivity, low concentrations of PM 2.5 (<50 μg/m 3 ) and CO 2 (<700 ppm) are recommended.