Numerical analysis to determine the performance of combined variable ceiling and floor-based air distribution systems in an office room

Abstract

This study analyses the performance characteristics of combined variable ceiling and floor-based air distribution systems in an office room using a numerical method to optimize the level of thermal comfort and indoor air quality. To validate the computational fluid dynamics simulations, temperature, air velocity and CO₂ concentration were measured and compared. The simulation results of various combinations of ceiling and floor-based air distribution systems show that the exhaust should be located above the occupant and the window in summer; due to the large thermal plume as heat sources that could be generated by the window and the occupant. Whereas in winter, the supply should be located on the ceiling far from the window and the exhaust should be positioned on the floor near the occupant; as the downward airflow around the cold window surface would become more dominant when compared to the upward airflow associated with any other heat sources. The results have indicated that having both ceiling and floor-based air conditioning systems would allow the flexibility to change supply and exhaust air diffuser locations to optimize thermal and ventilation performance more efficiently in countries that are subject to distinct seasonal changes.