Fans? Give me some info

What purpose are fans used? Heat? Humidity? Carbon dioxide? How much ventilation? Constant or intermittent? Noob needs to know.

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Welcome ! exhaust fan running. 24/ 7 an maintain negative pressure inside grow space filter and get rid of odor Also pull in fresh air. Circulating fans inside of tent cuts down on changes of mildew or mold. Hope that helps good luck.

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The answer is in short yes. Fans have a huuuuuugr effect on the entire grow environment.

Ventilation fans… create neg pressure and keep odor in check when used with a carbon filter. Depending on where your exhaust and intake are. It will remove heat and humidity as well. Its not as simple as it sounds tho…

Using humidity as an example… if the air inside tent is 70%RH and the air outside is 70% the fan will have no effect. However, if the air inside is 70% and the air outside is 30% then it will drive humidity down inside tent. The reverse is also true, if the RH inside is 20% and outside tent is 80% then humidity inside will climb. This dynamic works for temp as well in the same way.

The oscillating pedestal fans keep air moving inside tent. This does a few things… first if your running co2 it keeps it from puddling in certain areas. And keeps it distributed evenly inside tent. Second it it helps keep moisture in air suspended and not condensating on plants walls etc… this is where you need to understand humidity, relative humidity, dew point etc… can be pretty complex. In short no liquid moisture on plants equals less chance of mold mildew and bud rot.

Third reason for oscillating fan os the plant itself. If a plant gets blown around a little by a fan the plant is healthier thicker stalks, stronger internode joints etc… it really makes a difference when growing heavy colas.

There is lots more to it but that is the high school 4h version. Maybe some of our horticulture and agricultural experts can expound more scientifically.


Thanks, guys. Noobs need to know these things.

Thanks for the question @Grizzlybare
I am new too and was wondering the same thing.

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