Ventilation Systems in Greenhouses

Ventilation is essential to regulate temperature, humidity, and carbon dioxide concentration inside protected structures. Proper ventilation ensures removal of excess heat and moisture, prevents condensation on plant surfaces, and supplies fresh air for photosynthesis.

(a) Natural Ventilation

• Achieved through roof vents, side vents, and ridge openings.
• Relies on wind action and the chimney effect (hot air rises, cool air enters from sides).
• Saw-tooth and gable roofs are most effective in natural ventilation.
• Cost-effective, but less efficient in hot and windless climates.

(b) Mechanical Ventilation

• Uses fans, exhaust systems, and evaporative cooling pads.
• Exhaust fans draw out hot air while side vents or cooling pads bring in cooler air.

• Circulation fans are installed inside to ensure uniform distribution of air and prevent humidity pockets.
• Essential in regions with high temperature and humidity fluctuations.

(c) Hybrid Ventilation

• A combination of natural vents with mechanical systems.
• Offers flexibility, reduces energy consumption, and is effective in moderate climates.