Grow Room Fan Calculator

Room size

Fan parameters

Total air replacement every {{amount}} minutes in your growing environment

Is your result 2 minutes or less? 2 minutes or less is ideal for plants.
If not you need to increase airflow in your environment.

In smaller environments with high light levels (high heat output in a confined environment) you will ideally want to increase the airflow levels to ensure complete air replacement every 30 seconds. This is due to heat rising significantly faster in smaller environments. Eg. a closet with a 600 watt light etc.

Bigger filters represent better value for money in the long term and allow for better airflow (less percentage of air loss with the same fan).


Larger filters require less pressure than smaller filters because there is a greater surface area for the same volume of air to move through.


For approximately 30-35% more retail cost you can purchase twice the carbon (le. twice the life span) and get better airflow in the bagrain.

Speed calculator

Fill in known speed to any of the inputs

Other Ventilation Information

The tighter the bends are in your ducting, the lower the ventilation flow will be. Try to smooth out your bends as much as possible, and make them more gentle to increase flow.