Venting My 2x3x5.5 with PC Fans. Please Help!

[GreenPassion420]

Hey all! Thoughtful this may be my first post, I've been an active member of the mj community for years now, including participation on other well known sites. No high roller or nothin as you can see from my title! Alas, im still a noob, and still need some direction!

Anyway, ICM has contributed greatly to my knowledge of growing the sacred herb, and I have decided to venture into making a new cab for myself. I stumbled across a decent wardrobe style stand alone closet with removable sliding doors for $40 bucks. picked it up, did a little cleaning/fixing, installed some panda film and now im ready for ventilation! Only problem is, im not good with numbers/math or whatever. Simple formulas are ok, but looking in the ventilation sticky i froze up! Thats like a crash course in HVAC! I almost feel like certificates should be handed out at the end of it!

Ok, now onto the info I DO have. The actual dimensions are as follows:

W-37 5/8"
H-67"
D-20 1/2"

and the fans i have are as follows:

2 x Antec TwoCool 120mm (2 Speed)
High Setting = 1200RPM @ 42.6CFM
Low Setting = 600RPM @ 21.3CFM

2 x Antec TwoCool 140mm (2 Speed)
High Setting = 1200RPM @ 58.9CFM
Low Setting = 800RPM @ 33.6CFM

Ok, so According to the Ventilation Sticky, My Room Volume = 33 (L x H x D)

and my Recommended CFM(?) = 16.5(?). I got this from "Room Volume"/"MpAC of 2".

My Question is, will these 4 fans be enough, and how should I place them? Was thinking put the two 140mm fans on top and the two 120mm fans on bottom? Am planing to make an odor control box to vent into or whatnot. Still unsure of this, currently I have a custom scrubber i made form a 6" Booster Fan from Casa DePot and a Professional Air Intake for a car. Sorta works on my Rubbermaid Tub growbox and has a CFM of 80 I believe. Could potentially use this as well.

Thanks to anyone who actually made it through this, and more to any who can help a brotha out!

Peace out and stay green!

-GP

 

[budderfly]

I would start with doubling your room volume, not halving it. 16.5 cfm is barely any air movement. Even 66 cfm isn't that much.

The type of fans you have - axial fans - aren't very good at pushing or pulling air through a carbon filter.

It doesn't seem like the fans you have will be enough.

 

[GreenPassion420]

This is why im posting here. I'm not even sure my math is correct. And although i realize my fans aren't necessarily meant for this, I believe they'll do the job. I'm not attempting to scrub with these, more then likely ill have some sorta ona system going. I'm only having a few plants (no more than 5). I appreciate the response, but it seem's like you only had uninformative answers. No offense! I mean, IF my "Recommended CFM" for my room is 16.5, I would think all my fans at half speed could do that.... So stating there not enough makes 0 sense. Of course I'd like a bigger grow area, but that also has ZERO relativity to my question. Again, not trying to offend, maybe we just toked a bit before replying? It happens on these forums!

Anyway, thanks again!

Peace out n stay green!

-GP

 

[Bush Dr]

You need 2 air changes per minute for a space that small

PC fans won't do it

 

[budderfly]

IF my "Recommended CFM" for my room is 16.5, I would think all my fans at half speed could do that.... So stating there not enough makes 0 sense.

What I'm trying to say is that your "recommended cfm" is not 16.5. That's too low. Bush Dr agrees, double your room size for 2 exchanges per minute, do not half it that is too low.

And although i realize my fans aren't necessarily meant for this, I believe they'll do the job. I'm not attempting to scrub with these, more then likely ill have some sorta ona system going. I'm only having a few plants (no more than 5).

Without a carbon filter maybe the fans will provide enough air movement. Maybe. Of course, 5 plants, or 1 or 2 or 25 - it's going to smell. Only you can decide if that's an issue or not I guess.

 

[stagehand099]

You need to realize that PC fans cannot properly vent any growspace, period. End of story. You are doomed to failure if you continue to believe they will, Not trying to be harsh, friend, just trying to tell the truth....

stagehand

 

[soursmoker]

You need to realize that PC fans cannot properly vent any growspace, period. End of story. You are doomed to failure if you continue to believe they will, Not trying to be harsh, friend, just trying to tell the truth....

stagehand

you don't think it could vent a 1sqft veg cab using CFls for lights?

 

[GreenPassion420]

Ok, then my recommended cfm would be 66. Because for some reason, I must have read it wrong. ive seen people do roughly the same size cab with PC fans. My plan is to mount the two 140mm as exhaust and the two 120mm as intake. This wouldnt calculate out to 116cfm exhaust and 84cfm intake? Even at half that I would technically have enough no? Obviously they arnt optimal for the application, but I feel itll do the job for now, based on the nmbers I see. Like I said, im a noob, but I have nothing else aside from the 6” duct booster fan(forgot cfm rating), and no money ATM for a proper exhaust.

Again, thanks for help, im listening, I just dont see the point in spaming ”get better gear”, thats just ignant.

-GP

 

[stagehand099]

you don't think it could vent a 1sqft veg cab using CFls for lights?

Hey Sour, yes, I guess they could do that, but not well. And really, what effin' good would a 1 sq. ft veg area be? It might be fine for poppin' beans or rooting cuts in beer cups, but in 10 days, it wouldn't be so good. I understand some folks can't do more than microgrows but I'm still saying that PC fans suck balls at moving any real air. Personally, I think people who grow in PC cases and such are gluttons for puishment or high school kids.....

High School kids shouldn't be growing the herbs in their Daddy's house.

stagehand

PS Hey GP420, use the duct booster fan or buy another one. It will move more air than all 4 of those PC fans combined.....just sayin'

 

[Sativa Dragon]

Get a 4 inch squrriel cage should do ya fine but you will have huge odour issues, you should work in a carbon filter a 4 inch to match that fan if you want to sleep at night.

 

[soursmoker]

Hey Sour, yes, I guess they could do that, but not well. And really, what effin' good would a 1 sq. ft veg area be? It might be fine for poppin' beans or rooting cuts in beer cups, but in 10 days, it wouldn't be so good. I understand some folks can't do more than microgrows but I'm still saying that PC fans suck balls at moving any real air. Personally, I think people who grow in PC cases and such are gluttons for puishment or high school kids.....

High School kids shouldn't be growing the herbs in their Daddy's house.

stagehand

PS Hey GP420, use the duct booster fan or buy another one. It will move more air than all 4 of those PC fans combined.....just sayin'

thanks for the response and thats exactly what it would be used for. and I totally agree with you that overall pc fans suck balls. my only suggestion that could possibly work is split the lights in their own separate chamber with its own intake and exhaust fans. that would leave a very small area with a lot of the heat which is what pc fans are efficient at.

 

[budderfly]

Ok, then my recommended cfm would be 66. Because for some reason, I must have read it wrong. ive seen people do roughly the same size cab with PC fans. My plan is to mount the two 140mm as exhaust and the two 120mm as intake. This wouldnt calculate out to 116cfm exhaust and 84cfm intake? Even at half that I would technically have enough no? Obviously they arnt optimal for the application, but I feel itll do the job for now, based on the nmbers I see. Like I said, im a noob, but I have nothing else aside from the 6” duct booster fan(forgot cfm rating), and no money ATM for a proper exhaust.

Again, thanks for help, im listening, I just dont see the point in spaming ”get better gear”, thats just ignant.

-GP

You probably didn't even read it wrong, some people say half it but imho they are wrong. You also have to consider the space. A larger open space will cool better - a 10x10 room with separately ducted light hoods might be able to get away with halving the cfm, but that's irrelevant to you right now. Smaller tighter spaces tend to need

The thing is, you'll be right on the edge. 116 cfm? Theoretically, not realistically. Whether it will work for you is going to come down to the details - ambient temps, ability to move air through the cab from intake to exhaust well, what the cab's made of, what light you're using, phase of the moon lol.

Those are the fans you have if money's tight just run em and be aware that it might not be enough. If the temps stay ok great, if not you'll know it's probably too little air flow.

 

[GreenPassion420]

Thank you mate! I appreciate it! I heed peoples words and listen to advice, was well aware I should have a better vent system, but was mainly wondering if it was doable. Yes, its true that the number I came up with is only theoretical, but also keep in mind, I love the personal time with them and check daily, multiple times. Im running a few custom cfls that produce very small heat. im mostly just worried about fresh air exchange while im not peeping. I think for now it shall work. Only have two ladies ATM anyway.

 

[Sativa Dragon]

Right... Here we thought you had a real issue.

Why keep em in a tent at all why not move em around the house as you got time to tend to em from minutes past. Put them in the light and watchem grow. Why use a tent at al.

 

[oldone]

Hey GP,

(LxWxH)/1768 = 29.9 cuft for your setup.

With due respect for my brethren here, I think PC fans can vent your cab quite well.

What you didn't provide was your exact lighting in this space or your sensitivity to noise and smell. Let us know these details and we can help.

OO

 

[Trewarin]

Wait, what lights are you looking at running?

I have a 600w in a 2x3x5 stealth cab, and I run 16 exchanges per minute (440cfm centrifugal fan)

 

[soursmoker]

Hey GP,

(LxWxH)/1768 = 29.9 cuft for your setup.

With due respect for my brethren here, I think PC fans can vent your cab quite well.

What you didn't provide was your exact lighting in this space or your sensitivity to noise and smell. Let us know these details and we can help.

OO

this.

Wait, what lights are you looking at running?

I have a 600w in a 2x3x5 stealth cab, and I run 16 exchanges per minute (440cfm centrifugal fan)

I'm not saying it doesn't work but it's not the best environment for plants to live in a wind tunnel. if it works for you tho then right on bro! just lettin you know. you prob just have to water/feed more often

 

[GreenPassion420]

Hey guys, im only running cfls ATM, about 450w worth. I have basically a tent inside the cab to make it close t air tight, minus the fans of course, as far as smell, id say my sensitivity is medium-high lol. Been lookin into a smell solution, found a few ill mix together including ona buckets and possibly a custom tiny scrubber, loosly packed of course. Air fresheners, im afraid, will be my only solution til a most proper setup can be reached.

 

[oldone]

Hey guys, im only running cfls ATM, about 450w worth. I have basically a tent inside the cab to make it close t air tight, minus the fans of course, as far as smell, id say my sensitivity is medium-high lol. Been lookin into a smell solution, found a few ill mix together including ona buckets and possibly a custom tiny scrubber, loosly packed of course. Air fresheners, im afraid, will be my only solution til a most proper setup can be reached.

I cool my 220 watts with 2 PC fans running at about 50% speed which push air through a homemade filter. My cab is in the basement so ambient temp is cool to begin with.

This is the original design and shows the carbon filter. The fans are under it. The triangular hole in the foreground is the exhaust. The cab is meant to fit under the stairs (the top is not shown).


I think your biggest problem will be the air intakes. You can have powered or passive. Passive intake area should be 2x of the exhaust. Its hard to make the intake/exhaust light proof.

I've had many guests over sitting within feet of the running cab and they noticed nothing.

Good luck,
OO

 

[Mr.Bill]

I would just buy you a little 4" booster fan, and use the axial fans as intakes, that way you have multiple intakes, you can keep them on low settings as the negative pressure created by the small booster fan will keep them going at a good clip, thus extending the life span of the axials. You can get a booster fan at any lowes or home depot or comparable store. It's like 25 bucks. That way if and when you choose to upgrade to a scrubber, the booster should be enough to push a small one and then you just supplement ona or whatever for what might get out. Just my two cents if it makes sense.
~SB~

P.S. Welcome to the boards