Thermal Comfort in Existing Naturally Ventilated University Classroom: Validation of Measured Values by Simulated Values through BIM

In today’s world, it is necessary to conserve energy while maintaining a comfortable and healthy indoor climate in buildings. In tropical climates, individuals are exposed to longer durations of discomfort and a higher chance of developing health problems in buildings. The indoor thermal settings of a building have a significant impact on inhabitants’ health, productivity, and learning abilities. The study sought to validate the measured results of the existing naturally ventilated university classroom through parametric modeling and Computational Fluid Dynamics (CFD) simulation. The study compared the simulated results to the measured or experimental results to validate the accuracy of the building model created in Autodesk Revit. In Ghana’s Ashanti Region (Kumasi), experimental measurements were carried out between November and April 2023, during the dry season, and between May and October 2023, during the wet season. Data loggers (Testo data loggers) were used to capture data continuously for 24 hours. The indoor measured data and the indoor simulated results were compared. A comparison of the building model data and the existing building conditions was made to reduce errors. Classrooms ASBGF, FF, and SF recorded a difference of 0.15oC, -1.52oC, and -1.77oC between measured and simulated values with a percentage difference of 0.48%, 5.12%, and 5.82% for the dry season and -1.43oC, -0.09oC, and 2.46oC with a percentage difference of 5.60%, 0.30%, and 8.50% for the wet season. Negative values indicate that the measured data was higher than the simulated data. The dry season values were higher than the wet season values, and this was realized across all the measured and simulated parameters except the air velocity, which recorded higher dry season values for the simulation as compared to the measured values. The study concluded that the indoor space of the studied building was slightly warm, with a 43.66% discomfort level during the dry season, and cool with a 24.89% discomfort level during the wet season. The study recommended that architects should assess the thermal comfort conditions of existing university classrooms to ascertain the building’s comfort level for retrofitting. The study recommended that architects should use parametric building models for a whole building simulation to validate the measured thermal comfort of existing buildings for retrofitting.