Estimation model for natural ventilation by wind force considering wind direction and building orientation for low-rise building in China

Abstract

Building natural ventilation can effectively prevent the building from overheating and eliminate indoor pollutants, including viral aerosols and volatile organic compounds, without consuming energy. Natural ventilation by wind force is influenced by many factors, making it difficult to calculate accurately. This increases the complexity of designing natural ventilation systems. In this study, we use a computational fluid dynamics simulation and wind tunnel verification to determine the wind pressure coefficients of each facade of a cube-shaped building and draw their corresponding curves. Subsequently, we input the climate data of 31 major cities in China to analyse their potential for natural ventilation. The results show that although some cities have long ventilation hours, the wind-forced ventilation rate is relatively low. For example, cities such as Guangzhou and Nanning that were previously considered suitable for natural ventilation have relatively small ventilation rates that may reduce the cooling capacity of natural ventilation. The ratio, 0.12, of the average airflow rate to the local average wind velocity should be used to estimate the wind-ventilation rate during the early stages of architectural design to determine the total windows area in every facade.