Numerical study on natural ventilation of the wind tower: Effects of combining with different window configurations in a low-rise house

摘要

Wind tower is a traditional zero-energy natural ventilation device, which is capable of reducing building energy consumption and improving indoor environment. Many studies were conducted for its performance evaluation and design optimization, but most of them are more like underground applications. This paper aims to integrate the wind tower with single-sided natural ventilated house to arrange more desirable indoor air distribution. The ventilation behavior of the wind tower in a low-rise house was firstly compared with a common underground application. Then, effects of combining with different window configurations were investigated. CFD simulations were conducted using well validated numerical models. The results show that local wind environment must be well reproduced to accurately predict indoor airflow. Under the same incoming wind speed, the ventilation effectiveness of the wind tower in the low-rise house is 15%-40% lower than the underground application due to the effect of the separating flow above the roof. Optimizing the roof structure and slope to change the local flow field may improve the ventilation capability of the wind tower. When combining wind tower with different window configurations, setting a window on the windward wall is a more promising solution to improve cross-ventilation, since that the wind tower is in the negative pressure region above the roof. When the indoor temperature is higher than the outdoor, the exhaust wind tower will perform better due to the stack effect. The findings can provide practical implications for the performance evaluation and application of wind tower in contemporary house design.