Natural ventilation optimization of rural tourism homestays in North China: a parametric CFD-based study

The rapid expansion of rural tourism in China has driven the conversion of rural houses into rural tourism homestays (RTHs), many of which rely on energy-intensive systems for indoor climate control, raising sustainability concerns. Natural ventilation offers a low-cost strategy to improve energy efficiency and indoor airflow comfort, yet its effectiveness in RTHs remains underexplored. This study investigates wind-driven natural ventilation in three representative RTH typologies in North China, selected from previously optimized prototypes developed through a multi-objective optimization framework balancing energy use, daylighting, and thermal comfort. Computational fluid dynamics (CFD) simulations were conducted using the Butterfly plugin within Rhino/Grasshopper under prevailing summer wind conditions, and mesh convergence and discretization uncertainty were assessed using a three-grid Grid Convergence Index (GCI) analysis. Baseline simulations revealed that all typologies contained indoor areas with suboptimal ventilation. Optimization was performed on operable window openings, operable skylight openings, and courtyard configurations, and the tested parametric scenarios across typologies increased the comfortable velocity area ratio by up to 8.46% and the average air velocity by up to 2.42% (relative to the baseline) at the building or floor level. Finally, typology-specific passive design recommendations were put forward for RTHs in North China. The study further establishes a parametric CFD-based workflow for ventilation-oriented design optimization, contributing to low-carbon rural revitalization and evidence-based decision-making in sustainable rural tourism development.HighlightsExplores natural ventilation in rural tourism homestays in North China.Applies a parametric CFD-based workflow using Butterfly in Rhino/Grasshopper.Optimizes operable window openings, skylight openings and courtyard design.Proposes passive ventilation strategies for different homestay typologies.