Airflow, Ventilation & CO₂
Ventilation
Ventilation is the movement of fresh air into and out of a grow space to keep plants healthy and control heat, humidity, and odors.
What Ventilation Means in Cannabis Cultivation
In cannabis cultivation, ventilation refers to the system and process used to exchange air within a grow room or tent. Proper ventilation supplies plants with fresh carbon dioxide (CO₂), removes excess heat and humidity, and helps prevent pests, mold, and stagnant air conditions that can harm plant health.
Why Ventilation Became Essential for Indoor Growing
Historically, outdoor cannabis relied on natural wind and air circulation. As indoor cultivation expanded, especially in the late 20th century, growers recognized that enclosed spaces required active ventilation systems. Fans, ducting, and exhaust systems became standard components of indoor grow setups to replicate natural airflow and environmental balance.
How Ventilation Supports Plant Processes
Ventilation works by drawing fresh air into the grow space while exhausting warm, humid, or stale air. This airflow supports transpiration (the release of water vapor from plant leaves), which helps plants absorb nutrients and regulate temperature. Adequate ventilation also replenishes CO₂, a critical input for photosynthesis.
Managing Temperature, Humidity, and Plant Health
In cannabis cultivation, ventilation plays a major role in temperature and humidity control. Poor airflow can lead to heat stress, nutrient uptake problems, and fungal diseases such as powdery mildew or bud rot. Proper ventilation also strengthens plant stems by simulating natural wind and improves overall canopy health.
Components of a Cannabis Ventilation System
Ventilation systems typically include intake vents, exhaust fans, circulation fans, and sometimes carbon filters for odor control. Airflow should reach all parts of the canopy without directly blasting plants, which can cause windburn.
Common Ventilation Problems and Best Practices
Common challenges include insufficient airflow, poor fan placement, and noise or odor management. Best practices include sizing fans correctly for room volume, maintaining steady airflow, and regularly cleaning equipment.
Related terms:
Airflow, Humidity Control, Temperature, Transpiration, CO₂, and Indoor Cultivation.
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