I've read anywhere from 5 exchanges per minute - to 1 exchange every 5 minutes. That tells me it's really not that critical! I'm thinking that 2 or 3 exchanges per minute sounds about right. Let's hear what anybody else has to say, how many air exchanges per minute does your ventilation system provide?
How Much Air Is Enough?
- Thread starter T.H.Cammo
- Start date
Rurumo
Well-Known Member
I'd lean towards the 5 exchanges per minute-that will take care of potential heat issues and get your tent temps closer to your lung room temps. Good ventilation is key-I have an 8" AC infinity on my 4x4 and don't regret it at all. Big fan on small tent gives you a lot of flexibility and I find them to be much quieter on low speeds than the smaller fans on mid/high speeds.
Herb & Suds
Well-Known Member
I crank it up
As long as I’m not getting wind burn
I’ve heard arguments to the contrary but having grown in less than favorable conditions
More light and more air movement usually made it possible
As long as I’m not getting wind burn
I’ve heard arguments to the contrary but having grown in less than favorable conditions
More light and more air movement usually made it possible
Thanks for the replies guys. I agree with both of you, to a point. However; I have recently moved to Arizona and the RH here is absolutely arid, typically single digits to low teens! I find the excess humidity to be a benefit and I want to avoid the "Windtunnel Effect". With LED lights heat isn't really an issue and like I said, I want to retain the moisture level as much as I can - I just want to give them enough fresh air to "breath". With that being said: In my case; can I justify 2 or 3 exchanges per minute, or should I let 'er rip?
Anybody else?
Anybody else?
Herb & Suds
Well-Known Member
Maybe a swamp cooler till flower
Herb & Suds
Well-Known Member
I hear that!I lived there for a lifetime one summer
For what size of grow area?
420 Garden
Well-Known Member
I run an ac 8 inch in my 5 x 5 as well.
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Charles U Farley
Well-Known Member
For me, too much is never enough.
On the Fence
Active Member
portable swamp separate manual controls for pump, fan, oscillation. Behind the fill tray, I took a hot knife to the back so I could add ice if needed. Keeps tent at 80F/60-64RH
Pretty much turns off with the lights and small humidifier takes over unless further cooling is needed which it hasn't yet.
Pretty much turns off with the lights and small humidifier takes over unless further cooling is needed which it hasn't yet.
On the Fence
Active Member
My best friend is a engineer that designs computer hard drive cooling systems, big ones. I asked about having pusher and puller fans. He said absolutely not needed and can be detrimental in fact in most cases. He did go on to say that if the fans were matched CFM, came on and went off at the same time there would be little to no issue but no improved performance depending on the restrictions in the room. And then he went on to ask if this was a clean room or have dust in the air and the performance lost of dust on pusher blades vers pullers and harmful harmonics with both fans. Pullers are more efficient in dusty air and fans last longer. Something about how the particles collect on the blades vs the housing of the two types of fans. Also there is a difference between pusher fans and puller fans in how they are designed. He is obviously splitting hairs but that is what they do.
I should ask him if he has any models he could show us with our real world scenarios. Don't you just love to hate Brainiac's?
PopAndSonGrows
Well-Known Member
Leaving runoff in drip trays (as long as pots aren't sitting in it) can increase the RH around the plants as well.
On the Fence
Active Member
I got a quick reply.
There will be a system imbalance of the positive/negative pressure which can affect the fan motors and cause them to fail.
Cost twice as much to run but very little CFM gain out the end. You can only push so much through a fan at a certain rpm. You can increase pressure but not CFM so much.
If you need more airflow increase fan and direct flow in tent to where is needed not path of least resistance.
I'll talk to him more later after work.
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On the Fence
Active Member
I mop up with a towel and leave it hanging over the pot. Suc the pan dry as the pot sits down in it.
I don't see how you can maintain RH and temp if you are doing 5 air changes a min.
