What size fan do I need for 4x4 grow tent?

It's important to know how much fresh air you need to provide for a grow tent.The amount of air that needs to be exchanged is equal to the volume of the grow tent.If you are filling the space with accessories, there is more going into the calculation.You can learn how to find the CFM from our full grow tent guide.

Divide its length by its width and height to find its volume.As needed, convert units of measurement.This will equal your space's volume, with the required airflow equal to this figure.The formula looks like this:

A 48” x36”x72” grow tent converted to feet would be a 4' x3'x6' tent.72 ft 3 is the total of the dimensions.This grow tent has a base CFM of 72 since a grow space needs to beventilated every minute.

The next step is to increase the efficiency of your accessories.Adding components like ducting and carbon filters will make it harder for your fan to work.

The number of bends and sharpness factor into the resistance of the ducting.The straighter the ducting route the better, because airflow reduces the further it must travel.The sharper the bend, the less efficient it is, with a 30 bend cutting the amount of air by 20%.Smoothing outwrinkles can improve fan performance.

You have to account for the heat output of the grow lights if you are using them.

A high performing fan is required in order to move the calculated airflow.Depending on the type of component, you can use estimated efficiency percentages.

Our grow tent has a baseline CFM of 72.We add this figure to the efficiency percentage of each component.We get 166 CFM if we add a carbon filter, ducting, and a silencer to our system.The heat output of your grow light will give us a required CFM of 249.The percentages are not fixed and may change.This is the breakdown of the calculation.

If you add the ducting, carbon filter, silencer, and grow light heat, you'll get a required 249 CFM.