Negative pressure in grow tent

If I have a 6'' fan pulling 370 CFM into the tent from the room, will there be a negative pressure in the room strong enough to hear a 'woosh' sound from the air coming from under the door?

Pulling into the tent or out of the tent haha? Either way you're going to hear a 6in inline. I have a 4in inline exhausting air through a carbon filter and out the back of a 2x2x4 and there is intense negative pressure. You hear the air pushing out the back more than the fan, but you for sure hear the fan. My mac is 6ft away and at full volume it's pretty much just loud enough to hear music or tv. (Just the computer no speakers). You get use to the sound and don't notice it. But it's not discreet at all lol

There is a nice video on youtube that shows some ways of getting the noise level down. Even just putting the fan in a box brings a massive reduction in noise.

ANC said:

There is a nice video on youtube that shows some ways of getting the noise level down. Even just putting the fan in a box brings a massive reduction in noise.

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He's right.
I had mine in a box on the outside of the tent. Was in a cardboard box surrounded by blankets. Then that was inside another cardboard box with blankets in between both boxes (if that makes sense). It cut the noise in half for sure (it will help). A wooden sealed box would be ideal. Like he said there's stuff on YouTube.
Also not sure if you're new but make sure to get the proper cfl filter to go with your fan. There's a specific way it needs to be set up. All in all I was worried about the noise but it wasn't as loud as people make it out to be. Myself included haha. It's just not silent, if that's what you need...

Forgot to mention. I nixed the box and just strapped it to the roof inside the tent. More compact that way. Still a bit noisy but noise is less of a concern to me then smell. I keep a folded blanket under the tent and in top. Dampens the loud quit nicely

I don't think this has answered his question.

I doubt you would hear the woosh sound of air coming from under the door, but it's possible. The fan will draw air from anywhere possible. Depends on the size of the room etc.. If the window was open then definitely not.

As discussed, a larger problem is keeping the fan and exhaust quiet enough to bare. Definitely get a fan speed controller for $10 on amazon. This makes all the difference.I have my fan in a box stuffed with pillows.

sunny747 said:

I don't think this has answered his question.

I doubt you would hear the woosh sound of air coming from under the door, but it's possible. The fan will draw air from anywhere possible. Depends on the size of the room etc.. If the window was open then definitely not.

As discussed, a larger problem is keeping the fan and exhaust quiet enough to bare. Definitely get a fan speed controller for $10 on amazon. This makes all the difference.I have my fan in a box stuffed with pillows.

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Thank you

In a closet you would likely hear the woosh as the air passes under the door.

http://www.laskoproducts.com/blower-fan-multi-purpose-pivoting-utility-fan-model-u12100/

These things are the absolute best for a small grow. They are smallish , have a built in speed controller and two electrical outlets. The fan exhaust pivots. They are quieter than any other fan I have tried and move about the same amount of air.

I swear by these things, I've got multiple but have only ever needed one which has been on 24/7 for 4 years and still works as good as the day I got it.

The flange for the ducting is only about a half inch, so that can get annoying as they aren't designed for this purpose. Once your ducting on and taped with some strong tape I haven't had one fall off.

These are the quietest fans I've tried. Not noticeable outside the room the grow is in, but inside you can definitely hear it.

Removing air from the tent is better than bringing air into the tent. If you have the fan setup as an exhaust it will remove the hot air from the tent and bring new air in passively from the room. It's almost always better to remove the heat than to try and cool it.

sunny747 said:

In a closet you would likely hear the woosh as the air passes under the door.

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But obviously we cant answer that specific question because he would just have to try it and see lol.