Olfa Zghal

This study investigates the indoor microclimate of a large‐scale soilless greenhouse in northern Tunisia, analyzing its response to daily environmental variations through experimental measurements and numerical simulations. Structural and environmental factors, including glazing, ventilation, vegetation, and concrete ground, were assessed for their influence on the internal climate. The numerical model was validated through a grid independence study and by incorporating appropriate turbulence and thermal radiation models. Simulations with and without crops revealed that soilless cultivation significantly alters temperature patterns, with increases of 1 K above basil crops and 2.2 K above tomato crops. These variations highlight the strong role of crop transpiration in shaping airflow and temperature distribution. Differences between crop types were also evident, as basil and tomato cultivation induced distinct microclimatic effects reflecting their physiological and thermal characteristics. Central indoor temperature variations ranged from a 1.2% decrease between 13 and 16 h to a 2.4% increase between 9 and 13 h, with ground‐level maxima aligned with solar radiation. A predictive correlation was developed to estimate indoor temperature based on external inputs, offering practical tools for climate control. Thermal comfort indicators such as vapor pressure deficit (VPD) were also evaluated to guide crop‐specific climate management. The findings support optimized sensor placement, improved environmental monitoring, and the integration of crop effects into greenhouse thermal modeling. Designed as a representative case study, the experiment provides focused insights on plant‐climate interactions over a single day, serving as a foundation for future research on dynamic greenhouse microclimates.