Optimization of Natural Ventilation Strategies in Large-Space Buildings Based on Multi-Directional Wind Fields and Spatial Heterogeneity

Building energy conservation and emission reduction have become global priorities. Conventional sports facilities, owing to their substantial spatial dimensions, predominantly depend on mechanical HVAC systems, leading to elevated energy consumption and operational expenses. Consequently, the judicious application of natural ventilation is crucial for attaining a sustainable transformation of these structures. This study focuses on the National Fitness Center in Shenyang, a representative city located in a chilly climate. Utilizing the Ladybug Tools platform alongside computational fluid dynamics (CFD) numerical simulation techniques, multi-scenario simulations are performed for omnidirectional wind conditions and two varieties of window openings. An analysis is conducted on the indoor airflow distribution and wind speed characteristics across several functional regions of the large-space gymnasium under different wind directions. The study developed methodologies for identifying optimal ventilation durations and target wind velocities annually, quantified the influence of incident wind angles on ventilation efficacy, confirmed that appropriate building orientation can enhance ventilation efficiency by roughly 45%, and clarified the mechanisms and selection criteria for window types affecting indoor airflow patterns. The research findings offer a solid theoretical foundation and practical technical assistance for the ventilation design of national fitness centers to accommodate climatic conditions.