CFD-based multi-objective optimization of indoor air quality and thermal comfort in a classroom

Abstract

Comfort conditions and air quality in educational buildings can affect students’ performance, achievement and productivity, but they can also threaten their health. In this study, a sample classroom in Trakya University, Edirne, which lacks a ventilation system, is discussed. Depending on the determined parameters, an optimization study was performed using computational fluid dynamics. Predicted mean vote (PMV) for general thermal comfort, draught rate (DR) for local thermal comfort and the carbon dioxide (CO2) level for indoor air quality are selected as target functions. Outdoor air temperature, heating/ventilation system, insulation thickness, number of people in the classroom and clothing factor were identified as parameters that could affect the target functions. According to the numerical results, the rank of importance of the parameters affecting the target functions was calculated using the Taguchi method. The effect percentages of the parameters were determined using the analysis of variance. Then, all target functions were optimized with the grey relational analysis. The best case obtained as a result of the optimization has PMV, CO2 and DR values of −0.12, 511 ppm and 5.37%, respectively. When the general results are evaluated, a comfortable and healthy environment is provided in the classroom with the underfloor air distribution system operating at 100% fresh air and a reduced number of occupants.