Optimization of window design for ventilative cooling with radiant floor cooling systems in the hot and humid climate of Indonesia

The combination of ventilative cooling and radiant cooling is a feasible approach for improving the cooling performance of buildings, thus achieving better thermal comfort of occupants in hot and humid climates. We propose a novel radiant floor cooling system using a phase change material (PCM) in Indonesia. This study aims to determine the window design that optimizes indoor air flow pattern to provide ventilative cooling, while maintaining the radiant cooling effect during daytime. We analyzed several window types through a field experiment using an experimental building in Tangerang, Indonesia. The performance of the windows was analyzed with an air flow pattern and was assessed in convective heat transfers on the floors and by the standard effective temperature (SET*) at the center of the room. The results showed that the horizontal pivot windows led to air inflows to the occupied level regardless of the outdoor wind conditions. The heat transfer coefficient on the floor was reduced by approximately 1.52 W/m(2)K compared with that of the simple opening. Nevertheless, the increase in thermal mass owing to the PCM had a greater effect on the retention of the floor cooling effect compared with the effect of the window type. Consequently, the SET* was reduced by approximately 0.79 degrees C during the daytime, showing that the proposed window design with the radiant floor cooling system achieved better thermal comfort in a hot and humid climate. Particularly, the horizontal pivot windows contributed to thermal comfort mainly because of the ventilative cooling effect.

Automated summary

The study proposed a novel radiant floor cooling system using a phase change material in Indonesia, aiming to improve building cooling efficiency and occupants' comfort in hot and humid climates through a combination of ventilative cooling and radiant cooling. Experimental results showed that horizontal pivot windows facilitated air inflow and reduced heat transfer on the floor, contributing to better thermal comfort in the daytime.