Analyzing the real-time indoor environmental quality factors considering the influence of the building occupants’ behaviors and the ventilation

This study aimed to analyze the indoor environmental quality (IEQ) factors considering the influence of the occupants’ behaviors and the air change rate. For this, the real-time IEQ score was developed based on the indoor climate and air pollutant factors. This study was conducted from January to March at three offices, with the same room size but with different air change rates and used by people with different behavioral patterns. Three offices are based on a four-floor located in Seoul, South Korea, a monsoon climate region. The air change rate in Office #1 varied from 33.89 to 37.66 m³/h, with a median of 35.77 m³/h, and it was higher than that in Office #2 and #3. As a result, the number of occupants could be related to the CO₂ and TVOCs levels in all the offices. To keep the CO₂ level within the low range (1000 ppm), the number of occupants should be 3 (density: 0.25 person/m²) or fewer, and to maintain the TVOCs level within the low range (400 μg/m³), it is necessary to enhance the air change rate to minimum 9.0 m³/h∙person by changing the ventilation methods according to ASHRAE 62–1. At the same time, as there is much more fine particulate coming from outside than inside, the filter can be used in the window to allow the fine particulate to be exported. The results can be used as a building management strategy that simultaneously enhances the thermal comfort and indoor air quality using a real-time IEQ score.