How much cfm exchange should my homebuilt cabinet have?

flogger11

flogger11

New Member
Hey guys, I have apprx 25 cubic feet to exchange in a sealed cabinet, how much cfm is "just right"?

I have a C02 feeder system so I dont want to over exchange the air and I will be using LED lights so I wont have a bunch of heat issues, is once per minute (25cfm) about right? Or do I need to exchange the air more often? I want my plants to have time to soak up the expensive C02, I really dont want to be wasting my money. On the other hand I know plants need fresh air and that I dont want to under flow it either. Any help/opinions would be great.

Thanks for the input Pepes!

IMG00049-20100928-1216.jpg
 
Well man we're mostly stoner's so you have to be patient with us :p

To answer your question now :)

As a rule of thumb you should turn off your venting when your supplying CO2 to the plants (as to not waste any of it)

As for how much CFM to aim for:
The general rule of thumb used to be at least once a minute, but as far as I know this has changed to a minimum of 2 and optimally 3 times per minute so in your case either 50 or 75 cfm.
 
CannaRebel said:
Also have you decided on "when" as in what part of the grow cycle are you gona be supplementing CO2 in ?
Click to expand...

Well I purchased one of those "boost buckets" and I was planning on putting it on low while leaving it on 24/7 during my flowering stage. Dont think I can turn it off once it is started.

As for cfm I currently have a 50cfm fan but it has to pull through a scrubber so I was guessing 25 or so cfm is what I am actually going to get. Enough? Not enough guys? I was also going to leave my fans running 24/7.

Thanks for the help everybody!
 
I see, so you have a passive CO2 release system.....mmmmmm not a big fan of those tbh :/

I dunno what to say mate, at the same time you need to keep your ventilation just right as it is one of the most important contributing factors to a good yield (and to fighting mold/pests) yet at the same time you don't want too much venting since you will be wasting the Co2....


I hope someone with more experience / insight than me could pitch in on this dilema!

Anyone?
 
flogger11 said:
Fucking pricks
Click to expand...

Now there is a way to make friends!

My take is that, based on the time I've spent researching designs for my own box, if your 50cfm fan is going to be degraded to 25cfm and you need to exchange the air in the box 2 to 3 times per minute you're going to need a larger cfm fan or multiple fans. I'd rather have 2 smaller fans pulling 240cfm total than one fan all day..

Computer fans are pretty quiet and you could have say 2 120 cfm fans that are connected to either side of the home made carbon filter that pulls the air through the filter then out of the box. This little contraption can run across the top back side of your closet with one exhaust on either side and the carbon filter in the middle. Your light fixture is going to be in some of that space anyway and it won't take up any grow room.

Create a passive intake in the bottom part of the box, no fan and you're set. Then dick with it..if it doesn't seem to be doing the job, you'll find that out before you flower and replace the fans with larger fans. Judging by the look of your box, like me, you're not on a tight, tight budget and fans are cheap so if what you have isn't working, get new ones then sell the old ones on CL or eBay.

Figure out the cubic feet of your box then apply the appropriate cfm fans. There is a tutorial here about that..I read it this week...that's a long as I've been here.

I guess that's why I don't have to ask this question! DOH! lol

That's my take but then again....I'm just a fucking prick, right?? Good luck bro!

:goodluck:
 
Here is a link to a site where you could get a series of fans that plug into a thermal controller/timer that turn on and off depending on the temp in the box.

This is the direction I'm going. A pretty elaborate setup can be had for something like $100. That's fans, extension wires, the ac adapter, controller and even fan filters you could alter to include a flat carbon filter as a back up to a home made carbon filter..this is the bomb..

Coolerguys.com -- Your Computer and Home Theater Cooling Source for Over 10 Years

So...am I still a prick...no, sorry it was "fucking" prick...???

;)
 
flogger11 said:
200+ hits and no help... thanks for caring about my grow people, go f**k yourselves.
Click to expand...

I know the answer...





But I don't help a-holes that have no respect. There is this little tab up top called the search button for each topic, use it. Then maybe you won't be such a needy prick, we don't want those kind around here.
 
not to burst your bubble, cuz i know LED's are expensive, but the suck. but it is still possible to grow with them, so i wish you the best of luck. now to the cabinet. i also use a cabinet with CO2 that i make myself by mixing yeast and sugar in a bottle and letting it forment, the yeast eats the sugar and farts out CO2, cool trick right? and super cheap. well there are some rooms that are set up to where you don't need to vent out, but you do still need to scrub the air, and this is the part where your LED's help out. if they are gonna run as cold as they say then seal in teh cabinet and circulate the air inside the cabinet threw a charcoal scrubber and if the humidity gets to high then put an exhaust fan on a timer, say 15 min on 15 min off. the main reasoon to vent to 1) cool your room 2) bring in fresh air that has co2 in it to replenish the air that is CO2 depleated, and 3) to regulate humidity within the room. It looks like you might have 1 & 2 covered so keep an eye on three and if in seems to not be an issue then i could run a sealed unit
 

Similar threads

G
How much air exchange?
Replies
16
Views
4K
MostlyCrazy
M
HighWaterMark
Air Exchange in sealed CO2 augmented grow room
Replies
13
Views
13K
HizzyB
HizzyB
P
Calculating cfm for box w/ filter
Replies
3
Views
2K
Hogdady
Hogdady
L
Wall unit AC for grow cabinet?
Replies
2
Views
1K
sfhaze
S
woods brother
How much air exchange? Enough CO2?
Replies
0
Views
913
woods brother
woods brother
Back
Top Bottom