Implementation of ventilation towers in a greenhouse at the end of a slope: numerical approach to natural ventilation behavior

In a low and medium-technology greenhouse, the internal temperature depends on the external climate, the material, the design, the orientation, the type of crop and the location.
The ideal temperature in a greenhouse varies depending on the crop and its stages of development (the minimum temperature required for a tomato is 10°C, while 30°C could be the maximum temperature at which the plant develops naturally). The objective of this work is to evaluate the current conditions of the greenhouses and to simulate the effect that the implementation of ventilation towers has on temperature.
The environmental variables were monitored by installing temperature and relative humidity sensors inside the greenhouse and a weather station outside.
The record of environmental variables shows that during certain hours of the day, the temperature inside greenhouses is close to 40°C. This increase is caused by the location and obstruction of greenhouse windows (the proximity of some buildings and the distance between greenhouses). For the simulations, a computational model based on computational fluid dynamics (CFD) was built and used to analyze the thermal effect of the windows’ obstruction and the greenhouse’s location.
In addition, the implementation of ventilation towers was proposed to reduce the thermal gradient between the exterior and interior, increasing the airflow to the interior of the greenhouses.
The simulations’ results show that the windows’ obstruction and the greenhouses’ location cause a thermal gradient between the exterior and interior of up to 10°C, generating temperatures outside the maximum threshold for tomato cultivation.

International Symposium on New Technologies for Sustainable Greenhouse Systems: GreenSys2023

C.E. Aguilar-Rodríguez, J. Flores-Velazquez, G. Valdivias-Rojas, O.E. Aguilar-Rodríguez, E. Flores-Rodriguez, R. Morfin-Magaña

CFD, simulation, climate, warm period

https://doi.org/10.17660/ActaHortic.2025.1426.51