HELP! How do I fix a too-strong fan?

[Asha]

I have a 171 CFM Hurricane but even with my speed controller on low it sucks my 2'x4'x80" tent inwards- I've been having to leave the zipper cracked at the top to stop the tent from (I assume) eventually tearing. How do I fix this?

[uncledoug]

The tent should suck in some, yours seem to be a bit extreme. If you're growing autos just leave it open enough to reduce suction like you have been doing. Hopefully someone will have a better way.

[Asha]

Oh good, I was really worried about having the tent open but they are autos. Thank you!

[uncledoug]

You're welcome, happy I could help.

[Canuck147]

What kind of speed controller? Variable?

[Colombo]

Welcome to GWE Asha your at the right place ! Do you have any ventilation (air) coming into the tent. It appears you have a vent in the back bottom of your tent that can be used to adjust the neg pressure from the fan by opening it as needed (least light intrusion) but still maintain a neg pressure system without worrying about a collapse. Just a thought . Good Growing !!

[ribbitt]

I use a intake fan it also winds my plants

[Toker1]

Open the passive air ports located on the bottom of the tent. That will allow more passive air to enter the tent and will lessen the negative pressure inside the tent.
The first picture, it appears that the passive air port is closed on yours.

[Asha]

Is there a way to do that without letting in light or is it just a trade-off?

[Toker1]

Minimal outside light gets in. Unless you are shining a light directly in. No more light than a full moon night imo.

[Colombo]

Hey Asha, how did you make out with your ventilation system? Were you able to adjust the air intake/vents to relieve the vacuum ? Hope things worked out ! Good Growing !!

[Asha]

So far leaving the zipper open a bit at the top has been adequate but still messing around with things to figure out a better solution!

[BearsFan]

I have the exact same hurricane fan in a 3x3 tent and mine also did the same. As a poster above said, let more air in by opening up some ports on the bottom and your problem will go away.

[yellow]

Asha, perhaps try a less efficient route of the ducting. Create a few S bends, like a snake. That may hinder the flow.
If the duct is 6” maybe a 4” adapter could worsen the fans effectiveness.

[MBVapester]

You could try buying a vent pipe with a damper and attach it to the end of your exit duct and use the damper to reduce the air flow even more. On mine I put a T inside with 2 dampers to regulate how much recirculates and how much exits the tent area.

[Colombo]

Hello Asha, if you are still having problems, attached photo is of your tent and the vents we explained that you can open at the bottom part of the rollup flap and revelcro the sides so the bottom stays open allowing fresh air to come in and light out. Your zipper would allow more light in than the vents. Hope it helps. If you solved the problem than thats a good thing! Good Growing !!

[Asha]

Thank you so much for taking the time to do this! I opened up the vents and my tent is now fully zipped up with no issues!

[Colombo]

Glad you were able to solve your issue and get to growing without the added stress ! Good Growing !!