need some help with grow cab design.

[peterjoseph88]

Hey all hope everyone is doin well.so I just finished my first ever grow and everything turned out relly well actually.everything is hanging or in jars. Ill add pics later on tonight. But during my grow on days that were kind of hot (75+) my box got as hot as 90...not often but it did a few times, it averaged a high of 82 and low of 62. With the days getting warmer now I really need a re design.

Box dimensions
23"x19"x 5ft tall

I'm using a 400watt mh/hps,air cooled hood with a 4" fantech fan..I think about 150cfm pulling the air from the light out the top and pointed toward the window....and before I had a 4" axial fan for an intake and another 2 inch comp fan that propably did nothing...


So what I am thinking of doing is getting another 4 or 6" inline pulling air through a scrubber and out the top, my questions are...

How strong does the fan need to be to pull through a carbon filter and still create enough negative pressure for passive intakes to work?

And how big should the passive vents be? And how can I make the vents lightproof?

And is there any way to use one carbon scrubber for 2 inline fans? With ducting y's? Sorry for the flood of questions but its all I can think about and any help would be apreciated, ill add pics of the whole setup when I get home tonight so my rambling can make more sense.

Not sure if it matters but I plan to use 6" pots with about 9 plants sog style in ffof soil

 

[etinarcadiaego]

How strong does the fan need to be to pull through a carbon filter and still create enough negative pressure for passive intakes to work?

I have a 6" inline fan and it works well, about 400CFM

And how big should the passive vents be? And how can I make the vents lightproof?

I use 2X the surface area of my exhaust, I have 2 6" passive intakes and one 6" active exhaust.

Lightproof . . . you can make your own light-trap, or get darkroom louvers . . . . something like this.

And is there any way to use one carbon scrubber for 2 inline fans? With ducting y's?

I've seen it done, but never done it. Why may I ask?


Here's my homebuilt cab, before I added the second intake hole. It's 3ft x 2ft x 6'6"

 

[Clackamas Coot]

Here's my homebuilt cab, before I added the second intake hole. It's 3ft x 2ft x 6'6"

Very impressive. A very nice execution!

CC

 

[peterjoseph88]

Hey etinar.... thank you for the responce and suggestions, those darkroom louvers seem perfect I'm gonna look into them... as for using 1 carbon filter for 2 fans its because I need the smell covered and the heat pointed toward the window and the 6 inch I plan on getting would be pulling a lot of smell out and pointed in the right direction but the 4 inch is still unfiltered pulling air through the open end of the hood and outside, I just didn't want to have to get another filter


Edit: I Don't think that made any sense... I just want a way to have all ducting pointing the hot scrubbed air outside and not just into the room I'm in, since there is no direct exhause/intake.only the windows to the room the cab is in. I'll post pics later so it will make more sense

 

[inphu510n]

I think that for the space you already have excessive air exchange going on. Even if putting a DIY fan scrubber in there halves your air flow rate you're still pulling 70cfm through that cabinet.
What large air flow rates in this setup would be useful for is moderating humidity levels.
Though, I have no experience or knowledge about how passive intakes affect air flow...