Club 600

k thanks guys..how much cfm should i aim for

My closet grow was 27" x 38", and total vertical space was 6' from the shelf the plants were on up to the ceiling.
I live in Oregon (to give an idea of my ambient temperatures for comparison to where you live), and the 6" ducting through the light hood gets it's air from the room.
That uses the 435cfm fan, and is also good enough for when/if I need to add a medium-sized charcoal canister.

I have a 265cfm squirrel cage fan attached to 4" ducting that draws cool air into the closet directly from the air outside (through a window insert).
That fan is controlled by a thermostatic fan controller set at 80-f, and the fan cycles on & off every 3 to 5 minutes during the winter, and stays on full time in the warm months.
In the Summer, I replace that with a 3" hose from a portable A/C unit (I made a simple manifold out of a box so I can split the cool air into 3 hoses: one for my grow closet, one for the room it's in, and one routed to the master bedroom next to it.)

Some of it will depend on how much room above your light you have to keep the hot air up away from the canopy level of your plants.
If there is no room for the hot air to rise up, it will stay low in the closet and need extra cooling.
That was why mine needed the extra cooling: I only had about 12 inches above the light hood, and I filled it with pillows to help muffle the sound of the air whooshing through the openings of the light hood's ducts.

If your plants are on the ground and not grown excessively tall, and you have full ceiling height, you might be able to get away with less of a fan set up than me.

I use a 435 cfm 6" inline fan. That cools a 1000w in a 2' x 3' x 9' closet. I wouldn't get any less than a 6" fan.

Yeah, what jig said.
I only paid about $135 for a ValuLine 435cfm 6" centrifugal fan, and have been happy with it, except for the motor that's used is not totally compatible with a fan speed controller (will burn the motor out in about a year).
It's got such strong suction that I can remove the retaining straps that secures the 24"x 24" plate of tempered quartz glass to my hood and can't separate the glass from the metal frame until the fan is shut off.

lol i just had to get a speed controller for the bubble, with 25 feet of insulated ducting in front and 10 ft behind with backpressure my cfm on my 435 was almost cut in half....i knew because my intake which is passive from the inside of the house but is also 435 cfm was blowing up my bubble like a balloon. im running the fan at 45 % and they even each other out now while maintaining 77 degrees in a 10x 6 x 7 approx. room with 1 600. in the day i run a small space heater because of the backdraft i get and it being less than 10 degrees outside.....but all works now!!!!

Now once i get that second inline 600 nexto the first il step up the exhale to a 700+ cfm fan and run my 435 intake at 100percent power......hoping itl work

Flexible ducting is a airflow killer, for sure (from the rough surface, as well as the hose sagging, and from it compressing from the vacuum effect of the air flow. All are major influences on air flow).
I switched to 6" galvanized stove pipe for a smooth and quieter flow with the only pressure loss being from elbow joints, and 25-ft of pipe ducting.

well iv just been talking to a m8 who telling me one my other m8s just started growing and done hydro he isnt a smoker and just after making sum quick bucks as all other m8s are smokers so i hear he has pulled off 5 in a half oz bone dry off of 1 plant!!

im yet to find out what set up he was using and stuff il be onto that tomorow when i go for footy bet and see the lads and was thinking i might try a big wilma 4 pot in my 4x4 tent instead of 6 plants in soil in 10ltr pots just like iv done in my 3x3

any of yous use a wilma and could giv me a bit advice on them good or bad and what mediums they like using

DoobieBrother said:

Flexible ducting is a airflow killer, for sure (from the rough surface, as well as the hose sagging, and from it compressing from the vacuum effect of the air flow. All are major influences on air flow).
I switched to 6" galvanized stove pipe for a smooth and quieter flow with the only pressure loss being from elbow joints, and 25-ft of pipe ducting.

Click to expand...

Thats good info Doob.
My cheapo 8" ducting compresses almost flat at a bend and I loose about half my cfm.
I am gonna plump my new diy tent with what you suggested.

You'll also find that the noise from the fan is cut in half.
Most of the noise is from the inlet & exhaust openings being right next to the fan blades, so when you use stove pipe instead of flex-hose, it makes a big difference.

the reason i use insulated ducting is for cold and i also coil it to reduce sound, i know it reduces flow but when your nights are -20degrees Fahrenheit regularly u need the insulation. i also have 8" ports on my hoods but use a reducer to the 6 inch ducting. it makes it a bit noisey but once i attached my carbon filter i couldnt hear it at all. zero sound almost. with the bubble zipped up i cant hear it only the intake and with the door closed you cant hear that at all.

DoobieBrother said:

You'll also find that the noise from the fan is cut in half.
Most of the noise is from the inlet & exhaust openings being right next to the fan blades, so when you use stove pipe instead of flex-hose, it makes a big difference.

Click to expand...

I cut my noise in half with a speed controller and thats a waste of power.
I found 5' 6" 30 gauge for like $9

This last winter during the cold nights when the light is on, I had terrible condensation problems on the cool air side of the system.
Water was steadily dripping off the pipe all the way to the light hood, even with towels wrapped for insulation (can't afford actual insulation right now).
I eventually disconnected the cool air intake from the window insert and let it just draw air from the room.

i was contemplating running different light venting and room venting but i dont see the need right now, maybe when im running four 600s

doobie that is exactly what we have going on up here above 10000ft......remember the thicker insulation ducting is best, its got a black wrap on it, cant recall the brand.....another helpful tip i learned was to make sure the control box on your fan (where the cord comes out of) is on top and not below the fan where the water can short out and cause fire!!! At work we use 12" fans to cool multiple thousands in each flowering room all insulated and we still get drips from condensation on the fans alone. if the air is 15 degrees and the room is 80 you are going to get that no matter what you do.....we also run gigantic dehumidifiers for that reason in winter.

I hadn't thought about the power box being in the line of fire like that.
I'll be switching it up today.
It's not as much of an issue for me as I have my fan set up as a tractor fan (the fan is located at the exhaust-end of the cooling circuit), so the air is near room temperature by the time it's heading towards the fan.
But I'll still be changing it, as it makes no sense to take the chance.
Thanks for the heads up!

No worries man , youve thrown out plenty of gems on here.......

cannabiscult said:

lol i just had to get a speed controller for the bubble, with 25 feet of insulated ducting in front and 10 ft behind with backpressure my cfm on my 435 was almost cut in half....i knew because my intake which is passive from the inside of the house but is also 435 cfm was blowing up my bubble like a balloon. im running the fan at 45 % and they even each other out now while maintaining 77 degrees in a 10x 6 x 7 approx. room with 1 600. in the day i run a small space heater because of the backdraft i get and it being less than 10 degrees outside.....but all works now!!!!

Now once i get that second inline 600 nexto the first il step up the exhale to a 700+ cfm fan and run my 435 intake at 100percent power......hoping itl work

Click to expand...

is ur 435cfm on intake or to exhaust the heat from 600? 435cfm at 45% is 190cfm. and with 190 u can maintain 10 degree from ambient? clarify for me please

Speaking of 10,000ft, I once got high up on the peak of Conifer Mtn. with some Matanuska Thunderfuck during x-mas break from trade school in Denver, back in '87.

*well, got high several times during my visit up there

i run my exhale at full force because of the long ducting , it exhausts my room through my light.....


i run my intake which is also a 435 at 45-50 percent as to not blow up my flowering poly bubble....i do that becaUSE AT 45 PERCENT IT SEEMS TO MATCH THE EXHALE. I ALSO HAVE A 12 INCH oscillating fan on in the room moving air around. the room is 10x 6 x 7

My sister just informed me she won a partial lotto. Half million after tax, I'm stoked for her. She's never had things really good in her life and this is gonna get her into a home as an owner for the first time in her life. I just gotta tell everyone I know, it's like knowing someone famous! Well to me anyways