Spatiotemporal Reduction in CO2 by Occupants in a Classroom Using Organic Air Purifiers and an Extractor: A CFD Approach

In hot climates, classrooms are often air-conditioned to ensure thermal comfort. However, the classrooms remain closed throughout the day to prevent the entry of hot air from outside, which leads to a rapid increase in CO2 levels. In this study, thermal comfort and indoor air quality in a climate-controlled classroom are analyzed by implementing different configurations that consider the use of organic air cleaners, an extractor, variations in the air conditioning supply angle, and two different occupancy levels. The research uses computational fluid dynamics simulations to evaluate CO2 concentration profiles as a function of spatial coordinates and time. Vertical temperature differences for occupants are studied to analyze thermal comfort. Results indicate that configurations with three organic air cleaners, an extractor, and a 60° air-conditioning supply angle produce the largest average reductions in CO2 levels across the entire classroom. Furthermore, the vertical temperature differences for the occupants remain within permissible values. While experimental data support the reference case, the validated CFD model was used to predict the performance of the proposed configurations, establishing a foundation for future field implementation.