Effect of Airflow on Thermal Comfort in a Naturally Ventilated University Classroom

Abstract

The health, productivity, and learning capacities of the people who use a classroom are greatly impacted by the indoor thermal conditions. Airflow short-circuiting, draft discomfort, and uncomfortable temperature stratification are just a few of the issues that can arise from inadequate air distribution in a classroom. The Classroom ESABSF was selected for the airflow analysis on thermal comfort in a naturally ventilated university classroom. The selection was based on the indoor thermal environmental conditions measured and simulated. The Classroom ESABSF, which measures 24 x 25 x 5m (length x width x height), with a north south orientation along its length. A corridor connects the room's eastern and southern sides to a main entrance door, and portions of the room's east and south faces feature glass louvers, each with six operable windows. During the studies, several window opening configurations and locations were employed to examine the variance in the room's ventilation characteristics. Ten simulations were run, with five including occupancy and the other five without occupancy. The average air temperatures and velocities were anticipated and observed at a level of 1.1 meters above the floor. Average air https://zenodo.org/records/15332652 Page 6 temperatures and velocities in the classroom, which were 1.1m above the floor, were measured and predicted. The Classroom ESABSF recorded (with occupancy) relative humidity, indoor air temperature, and indoor air velocity, PMV, PPD, and thermal sensation of 32.55oC, 0.95m/s, 62.72, 97%, and hot, 29.01oC, 0.95m/s, 78.45%, 69% and slightly warm, respectively for the dry and wet seasons. The unoccupied Classroom ESABSF recorded relative humidity, indoor air temperature, and indoor air velocity, PMV, PPD, and thermal sensation of 31.08oC, 0.88m/s, 59.63, 81%, and warm, 28.43oC, 1.02m/s, 85%, 49%, and cool, respectively, for the dry and wet seasons. The study concluded that an increase in air flow decreases the indoor air temperature, relative humidity, and radiant temperature. The occupied classroom was uncomfortable during both the dry and wet seasons as compared to the unoccupied classroom. The study recommended that architects make all efforts (wall-to-window ratio) at the design stage to increase air flow in naturally ventilated classrooms. The number of students in a classroom should be calculated according to the total floor area of the classroom to avoid overcrowding of the classroom.