Study on Hybrid Cooling System coupled with Radiation Panel Cooling and Natural Cross Ventilation : Part 2-Application of Hybrid Cooling System to the Hot and Humid Regions

Abstract

The effectiveness of a hybrid cooling system using radiation panel cooling with wind-induced cross ventilation in an office setting is investigated. Differing from an existing hybrid system, the hybrid cooling system suggested by this study introduces outdoor air with natural ventilation even when the outdoor air is unfavorable to cool the indoor environment. For this purpose, the system is devised on a strategy that utilizes stratified room air with a vertical temperature gradient. The air cooled by the radiation panel settles down within the lower part of the room, while the hot and humid outdoor air introducing through ventilation inlet passes through the upper region of the room and sweeps out the heat and contaminants generated in the room. The characteristics of the indoor environment are examined using CFD (Computational Fluid Dynamics) simulation, which is coupled with radiation heat transfer simulation and with HVAC control. In this paper (part 2) the performance of hybrid cooling system with radiation panel cooling is analyzed under hot and humid regions. The relations between the characteristics of thermal stratification of the room and system design parameters (ceiling height, cooling panel height and ventilation opening height) are analyzed. Even in severe outdoor condition, the hybrid cooling system with radiation panel cooling system is more energy-efficient than an underfloor air cooling system when introducing wind-driven cross ventilation.