Impact of design features on natural ventilation of open-air malls in Thailand

Abstract

In recent times, retail buildings in tropical areas have started to evolve from fully enclosed air-conditioned designs towards designs featuring open-air naturally ventilated malls. This paper discusses influential factors that can be used to help achieve thermal comfort conditions in the semi-outdoor spaces of open-air malls within the Bangkok Metropolitan Area in Thailand. The researchers surveyed 23 buildings and categorised them into three groups according to their configurations. Six representative projects were selected and assessed using a computational fluid dynamics program. The results revealed that the percentages of thermal comfort hours varied from 34.7% to 80.8% of the annual occupation time and were highly dependent on the design decisions taken for individual projects. The study found that among five important design factors, which are position of openings in accordance to the prevailing wind, distribution of openings, window-to-wall ratio, building shape, and openings that encourage cross-ventilation, the first factor was the most influential. Buildings that have their position of openings in good accordance to the prevailing winds can achieve the number of hours 2.0 times greater than those that do not.