Airflow Inside Vertical Grow Racks: Managing the Microclimate

A room-average temperature and humidity reading can hide very different conditions inside dense multi-tier canopies. Rack airflow should be designed and measured at the plant level.

Measure each tier

Place sensors or take representative measurements at multiple rack heights and positions. Supply air, return air, walls and aisle exposure can create different microclimates.

Avoid stagnant canopy zones

Dense foliage slows air movement. Local circulation can help mix air through the canopy, but fan position and speed should avoid excessive plant movement or direct drying.

Coordinate airflow with dehumidification

Moving humid air out of the canopy is useful only if the facility can remove the moisture. Rack circulation and room HVAC should be designed together.

Allow the system to follow the crop

As plants grow, the canopy height and resistance to airflow change. Adjustable airflow or equipment positions can help maintain consistency through the crop cycle.

Verify with plant-level data

Compare tier-to-tier temperature, RH and VPD trends rather than assuming the rack behaves like the room sensor.

See the P20 Grow Ventilation System and PURE Smart Grow Systems.