CarbonActive FanBox

Why do I need to ventilate my grow tent?

During plant cultivation, large amounts of water vapor are released into the surrounding air. This moisture must be removed to maintain optimal growing conditions.

There are two ways to achieve this:

1. Active dehumidification in a closed system
2. Supply and exhaust air ventilation in open or semi-open systems

💡 Pro Tip: The amount of water released into the air is approximately equal to the amount of irrigation water given to the plants. However, you should subtract the portion of water that drains from the substrate as runoff or wastewater.

Formula:

Daily irrigation water – wastewater = transpired water

A grow tent or cultivation room can be ventilated using an exhaust air fan. To prevent odors, it is recommended to use an activated carbon filter in front of the fan.

Since carbon filters and ventilation ducts create pressure loss, it is important to choose an exhaust air fan with sufficient power to compensate for these losses and maintain proper airflow.

For open systems, a recommended air exchange rate is 30-60 times per hour. This means the air inside the grow tent or cultivation room is completely replaced 30-60 times per hour.

This ensures that during high transpiration phases, especially in mid-to-late flowering, enough dry air is supplied to absorb plant moisture and effectively remove lighting heat from the cultivation space.

A high air exchange rate is especially important during summer, as outdoor air tends to be warm and humid.

Since humid air has a limited ability to absorb additional moisture, insufficient ventilation can lead to humidity buildup, increasing the risk of mold and plant stress.

Eine hohe Luftaustauschrate ist besonders für den Anbau im Sommer nötig, wo die Außenluft an sich oft bereits warm und feucht ist.

Denn bereits feuchte Luft kann nur schlecht

When handling high airflow volumes or operating a fan at its maximum capacity, increasing the diameter of the exhaust duct can help reduce noise levels by minimizing airflow resistance and turbulence.