The effects of void combinations at rectangular plan high rise residential building to the natural ventilation performance

Abstract

The natural ventilation in living units of high-rise residential buildings are commonly assisted by mechanical ventilation systems to achieve desired indoor environment quality. The usage of mechanical ventilation is also due to different reasons like the climate condition and the overall buildings design. However, because of its disad-vantages, such as the negative impacts on the occupants health and the overall energy consumption, there is a necessity to ameliorate natural ventilation performance as a passive cooling strategy. Improvement made through suitable design configurations to improve the internal environment quality may reduce heavy electricity consumption. Hence the research aims to investigate if the integration of voids combinations as pas-sive design feature in high rise residential buildings can enhance the indoor air velocity in the living units of high-rise rectangular plan residential buildings. The hypothesis is good control of the configuration of voids combinations can lead to better naturally ventilated living units. The research evaluates the introduction of various horizontal voids sizes and positions, combined with the commonly used vertical voids to opti-mize natural ventilation. The methods used in this research are the field measurement as a full-scale experiment and the computational fluid dynamic (CFD) simulation using Ansys CFX. The results of the high-rise residential buildings inventory were used to determine the appropriate building for the field measurements. The validation of the CFD building model against the field measurements data ensures the reliability and the accuracy of the CFD simulation. CFD simulation includes three main experiments which are the CFD building validation against the field measurements data, the effects of voids combinations on the air velocity inside the voids of building models and fi-nally the influence of the proposed voids combinations on the internal air velocity in the living units of the building models. The experiments are done in living units under different openings conditions located at different heights and orientations. This study found that the provision of double-sided horizontal voids larger by 50 % connected directly to central vertical void can improve the indoor air velocity (m/s) in the living units by 1.23 % to 0.179 m/s under north east (NE) and by 4.59 % to 0.165 m/s under east (E) wind directions. The suitable voids combinations were recommended to im-prove the natural ventilation performance. This study contributes to a better under-standing of ventilation performance in high rise rectangular plan residential buildings designed with voids configurations. It also recommends the possible voids combinations as design strategy for indoor air velocity (m/s) performance in the living units of the high-rise rectangular plan residential buildings in Malaysian for adequate thermal comfort level.