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Passive air intake flaps

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Growmie
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Passive air intake flaps

Post by Growmie »

How many do I have open? At first I only had one open but the air only being drawn from there seems to be causing the closest plants to get windburn/curling. I tried to open them all but to even get some negative pressure I have to have the fan running really high. I don't mind but the fan is oversized for the tent so I'm struggling with balancing negative pressure/wind speed etc.
I've settled on two for now but still not sure if it's right?

Any advice would be much appreciated. :thanks:

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Re: Passive air intake flaps

Post by 2-Scoops »

1 or 2 should be fine, i run a passive inlet myself in my grow cupboard. I've always gone by x1.5 to x2 times size passive inlet hole to your extraction fan, but i see your running oversized gear. But yes i would think 2 is more than enough in a smallish grow tent.
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Growmie (Wed Oct 06, 2021 10:38 pm)
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Re: Passive air intake flaps

Post by E.p_grower »

What size tent and what CFM is your fan?
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Growmie (Wed Oct 06, 2021 10:38 pm)

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Re: Passive air intake flaps

Post by Growmie »

E.p_grower wrote:
Wed Oct 06, 2021 9:19 pm
What size tent and what CFM is your fan?
100x100x200 AcInfinity S6 405 max CFM iirc.

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Re: Passive air intake flaps

Post by Growmie »

2-Scoops wrote:
Wed Oct 06, 2021 1:16 pm
1 or 2 should be fine, i run a passive inlet myself in my grow cupboard. I've always gone by x1.5 to x2 times size passive inlet hole to your extraction fan, but i see your running oversized gear. But yes i would think 2 is more than enough in a smallish grow tent.
Thanks mate, two open seems better than one at the moment as one on its own causes too much of a kind of wind vortex and was stressing the smaller plants. With two though it seems fairly stable. Thanks mate!
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2-Scoops (Thu Oct 07, 2021 11:49 am)

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Re: Passive air intake flaps

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Growmie wrote:
Tue Oct 05, 2021 8:15 pm
to even get some negative pressure I have to have the fan running really high. I don't mind but the fan is oversized for the tent so I'm struggling with balancing negative pressure/wind speed etc.
Negative pressure isn't all it's cracked up to be - it makes no difference to the plants and is really just about making sure that the smell doesn't esacpe before passing through the fan and filter.

Perhaps consider a an auto transformer (Variac) to reduce fan speed and noise? I've had one for a while and wouldn't do without it now. (Don't get the "dimmer switch" type of controller unless you want a much noisier fan!)
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duke (Fri Nov 19, 2021 8:17 pm) • 2-Scoops (Fri Nov 19, 2021 9:20 pm) • Budgie (Mon Dec 06, 2021 2:23 pm)

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