Ventilation removes heat and moisture and helps shape the crop environment inside a protected structure. The required approach varies between hotter lowland sites, valley locations and cooler high-elevation areas.
Natural ventilation relies on the size and position of openings and on local wind and temperature differences. Insect net can reduce airflow, so protection and ventilation should be considered together.
Where natural ventilation is not enough, active ventilation or cooling may be considered. These systems add electrical, water and maintenance requirements and should be justified by the crop and production objective.
Do not select a ventilation package by greenhouse area alone. Structure geometry, local weather, crop canopy and operating practices all influence the result.