Ventilation In The Grow Room

A good ventilation avoids the build-up of humidity and the elevation of temperatures in the grow room

9. Ventilation In The Grow Room

The ventilation in the cultivation area and in general the circulation of air is an important primary factor. As seen in the previous chapters a good aeration helps the cultivation avoid the build-up of humidity and excess temperatures.

The process of air extraction, therefor becomes fundamental and its objective is to extract air and recycle in the indoor area every 4/6min. An air treatment set-up is thus composed of the following products:

  1. the extraction fan
  2. the aluminium flexible air duct
  3. ventilator for fresh air emission
  4. fan( to help the total air circulation-optional)
  5. carbon filter (to eliminate odours-optional)


 Choosing the size of the ventilation system:

An extractor fan is chosen mostly on the basis of the capacity. To calculate the necessary size, multiply the volume of the grow room/grow box by 70. To choose the fan use the following equation: Height x Width x Length x70 = Capacity

Once calculated the capacity of the extractor fan needed, we can then choose which model. Once having chosen the model and diameter, its necessary to choose the air ducts, making sure the diameters correspond, or if a size adapter is necessary.

To attach the fans and ducts junctions or ducting tape can be used.

It is also possible to automate the ventilation system by using control units which function by regulate the power and velocity of the fan based on the set parameters of humidity and temperature.

To find out more in depth follow the guide for the choice of air treatment set-up.


Caron dioxide (Co2) in the grow room:

When cultivating indoors, it is possible that the plants in the growth period absorb a lot of Co2, if this occurs it can slow down notably the growth of the plant.

To maintain high levels of Co2 in the grow room, it can be sufficient to let fresh air in the grow room with a fan. However too much air circulation can lower excessively the temperatures, and in this case we can integrate a forced delivery of co2 directly with co2 release system.

To calculate the optimal quantity of Co2 in the grow room- click here

Calculation for air flow exchanges and extractor fan capacity

Unit of measure

Room size
XX m

Room volume

Type of room/environment

N° of Air exchanges

Air capacity m3/h