Carbon filter & fan size for 3x3x6.5

Sp33dymonk3y

Active Member
Well title says it. What size of carbon filter and inline fan for a 3x3x6.5 passive intake :o 3 rectangle mesh holes bottom of tent to let air pull in from. I was thinking I could maybe get away with a 4"???
 

2004play

Well-Known Member
i have two 4x4 tents the newest one I cheaped out and picked up a 4" fan/filter and regret not getting a 6" like the other tent has
The temps are fine in both but the 6" scrubs the air so much better than the 4" I exhaust inside another room so I will be upgrading to another 6" in a few weeks the 4" is a bit quieter than the 6" but I can run the 6" just over 50% speed and it's near silent outside of my setup
Both tents have a 600w
 

Sp33dymonk3y

Active Member
I keep seeing com many place that the 6" for a 3x3 is over kill.. So I may just go with the. 4" ven tech (; like $80
 

nomofatum

Well-Known Member
6" is way over kill for 3x3. You want to clear your air every 2 minutes. So calculate your cubic feet and divide by 2, this is the actual CFM you want to be running at. Note that actual CFM has little to do with the max CFM on your fan is rated to.

Actual CFM can be estimated if you find the CFM/pressure curve for your fan, and compare to the static pressure rating of your filter + a bit for ducting.

At 58.5 cubic feet you want to be able to set your exhaust to about 30 actual CFM.
 
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Sp33dymonk3y

Active Member
The 4" has 190 cfm I guess is max? So that would work great? Everyone keeps posting about 4 x4 tents lol that is 1x1 more! That's a lot! lol thank you, you have me a huge relief.. And saved me from spending double and over killing (:
 

nomofatum

Well-Known Member
The 4" has 190 cfm I guess is max? So that would work great? Everyone keeps posting about 4 x4 tents lol that is 1x1 more! That's a lot! lol thank you, you have me a huge relief.. And saved me from spending double and over killing (:
It's again overkill, but once you add ducts, a carbon scrubber, and a fan controller you can get it down to a reasonable speed. That is the option I would go with.

190 would be it's CFM rating with no static pressure or 0.0" WC. Add 20ft of ducts, 0.15" WC, add carbon scrubber .35" WC = .5" WC total = likely around 100 CFM actual

100 CFM would clear your space quicker than needed or wanted, add the fan controller to allow you to adjust down and you should get something reasonable.


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nomofatum

Well-Known Member
The above picture is from the tjernlund fans. You can see with a M-4 fan and 0.5" of static pressure would still be 160 or so CFM. Most fans drop off faster than the tjernlund.
 

nl5xsk1

Well-Known Member
Yeah, good info there!, I have a 4.5 x3.5 x 6.5ft,room, and use a air cooled 600 hps, phresh scrubber along with a 4" in-line fan. (also use a phresh silencer and a fan controller). I also use a small 110vac computer fan as an in-take fan.(located at the base board) This room runs completely smell free, avatar says it all. Oh yeah, the scrubber is a 6"reduced to a 4 " duct then through the light and out it goes
 
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Mo!

Well-Known Member
I run a 3x3x7 tent with a 600 hps. I do air cooled hood and my ducting goes filter to hood to fan and out. I'm currently using a 4" with a can 2600 and it works to keep my temps right in the 70s. However... After having run this setup for over a year I would definitely suggest going to a 6". Reason being if I need to up my fan speed (let's say summer time and it gets warm in the basement) and I'm running a stinker strain, I find that it doesn't always allow enough contact time with the carbon filter to truly filter the smell. I could most likely skip this problem by just having dedicated ducting and fan for the hood but I wanted to keep it as minimal as possible.

You really can't go wrong oversizing what you need just a bit when it comes to air and smell control IMHO.
 

ShirkGoldbrick

Active Member
Whatever size they rate it for..double it or more. I have some gg #4 vegging in 4x4 tent and a 6" fan/filter combo can't scrub the air clean.
 

OldSchoolBud

Active Member
Whatever size they rate it for..double it or more. I have some gg #4 vegging in 4x4 tent and a 6" fan/filter combo can't scrub the air clean.
Good advice, only wish I had a clue what GG #4 was though. I'm afraid of really stinky strains that can overwhelm a carbon scrubber. I've always shied away from diesels and cheeses because I don't want the paranoia of worrying about the smell. Anyone have a clue what GG #4 is?
 

ShirkGoldbrick

Active Member
Gorilla Glue #4 by Joesy Whales, clone only. It's got unusually dark foliage and demonstrates a twist/curl to the younger leaves. People are pulling 2 elbows per light without a ton of effort. strong scent.
 

OldSchoolBud

Active Member
Gorilla Glue #4 by Joesy Whales, clone only. It's got unusually dark foliage and demonstrates a twist/curl to the younger leaves. People are pulling 2 elbows per light without a ton of effort. strong scent.
Thanks for the quick answer....guess I don't have to worry about that one since it's clone only. Just wanted to know what to be on the lookout for in the future, because I sure don't want to grow stuff that over powers the carbon scrubber. Thanks again.

Gorilla Glue is a cool name though, sounds like it would glue you to the couch. haha
 

NYFlowerpower631

Active Member
Threads old haha but I run my AC Infinity cloudline 6” with a Phresh 400 cfm eating with absolutely no smell and I grow some seriously smelly dank strains gg#4 being one of them Gelato, Tangerine Dream some serious smelling shit and only time you smell them is when I open tent. And literally you have to stick your head into tent. I also hand the odor bag 2 of them hanging up near the carbon filter. Can also by ona gel and actually put it inside the carbon filter for extra smell removal
 
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