Experimental and CFD-based performance optimization of ceiling, floor and air cooling systems using Taguchi analysis under summer overheating conditions

Standards for HVAC design prescribe ranges for material selection and installation, yet further optimization is needed to address specific challenges such as solar radiation effects that cause indoor thermal imbalance in summer. This study presents a preliminary sensitivity analysis of summer cooling performance in buildings, focusing on system selection, structural design and cooling energy demand. An integrated approach combining experimental tests, computational fluid dynamics, and Design of Experiments was applied. A test cell equipped with three systems, Ceiling Cooling System, Floor Cooling System, and Air Handling Unit, was used for comparative analysis. The validated CFD model was combined with Taguchi design and ANOVA to identify dominant factors, and contour-assisted optimization was used to refine feasible operating ranges based on PPD and cooling energy demand, E _c . Results indicate that the Air Handling Unit provides the strongest cooling response but requires coordinated control of inlet temperature and airflow to limit draft-related discomfort and E _c . The Ceiling Cooling System offers a balanced compromise between thermal stratification, comfort, and cooling demand, while the Floor Cooling System shows lower calculated E _c within the adopted calculation boundary but less uniform comfort under sun patch exposure. Findings provide guidance for optimizing summer cooling strategies.