Ventilation help needed asap!!!


  • Hi guys,

    right a brief description on grow room ect -

    i have a small cupboard (closet) with a grow tent placed inside, running a 600w air cooled hood, intake fan 4'' and outtake fan 5''
    there is no windows in cupboard (closet) so i cut a hole and ran the ducting that carries my hot air (outtake) out of the room, however my temps are
    still flying high im talking around 32c, could some one please advise me of a way to sort the temp prob? i also have 2 6'' clip on fans in there.
    its only a 4 plant grow so could the 600w be a bit of over kill?

    thanks in advance for your help and advice

    20130108_164634.jpg
    • 20130108_164646.jpg








 

lykarckstar420

Active Member
Yes For the space 600W in my opinion is too much .. Does your ballast have an adjustable setting ?? If so try toning it down to 400W ish .
 

Mcwhippin420

Well-Known Member
Also get a good tower fan to put in there and place 1 of your clip fans about 2 inches under light on one the sides of cupboard blowing the air right thru under the bulb and put your other one on your babies until you get a tower fan then just put it on rotate it helps a good bit
 

Blowin' Smoke

Active Member
You need a pretty decent fan to cool that light in that small area. At least in the 400 cfm range. Is your tent going to be in a air conditioned room? Do you have negative pressure? Meaning does the fan pull your door shut slightly?
 
no the room is not air conditioned and my light is a sealed air cooled hood yet still temps are high, i done a bit
of re arranging and now have them down to 29c however my cool air intake is taking the air from inside my room which my tent is in
but due to nosey people i cant cut anymore holes so i could do with some suggestions please
 

Blowin' Smoke

Active Member
So 29c is like 84 degrees? That's not terrible, but would be better lower. Even a air cooled light is gonna put off heat. My light adds roughly 7 degrees when everything is running, so if it's 80 degrees in my garage ( sorry don't know celsius) it's 87 in my grow closet. That's why I have to run AC three or four months a year. Everything adds heat, fans, lights, ballasts ect.

You only need so much intake. I have filter/fan combo, not completly sure of the cfm because it was givin to me, but i'm pretty sure it's like 440 cfm. Filter/fan goes to a 6" duct which goes to the light, then on the otherside of the light I stepped down to a 4" duct. Duct blows out of the closet into the vented garage. My passive intake is roughly 5" by 10" cut in the drywall. I started with a smaller hole and felt the pull when opening the door until I thought it was about right. Does your cabinet door kind of close itself from the draw of your fan? I'm just wondering if you have good airflow.

Just remember in a perfect world the temp would be 78 and you would have a 10 to 15 degree drop when the lights went out and the plants would love you, but it's not a perfect world when you have to grow in a small space in secret so just realize that it's great to strive for perfection, sometimes perfection can't be obtained. That being said if your high temp is 84 it will grow just fine. Would I prefer it lower yes but you will still get some of the best smoke you ever had growing your own.

Things you can try: obviously air condition room, exhaust heat from cab. outdoors if possible, because your warming the air thats going right back in the room (ambient temp), run lights at night when temps are cooler and costs are cheaper, get the mechanicals out of the box (hard to do when your trying to be stealthy) feel the heat comming of your ballast alone.

My closet is roughly 4'w 2.5'd 8't and it was 82 degrees in there this morning. Todays forecast has the high temp at 83 degrees. So right now i'm roughly at the same temp. as you. Nothing I can do about it unless I hook the AC back up. I only worry if the heat gets in the 90 range.

Well good luck and hope I was of some help, it's hard to figure out without actually being there.
 
yeah 29c is 84.2f its not to high i know but i still would prefer it around the 26-27 mark, at present my intake duct is in the same room but hooked up out side of my tent
if that makes sense, so im thinking i need to cut a hole in the wall and run it totaly out of the room? the prob with this is i need to keep it stealth as i do have nosey
visitors at times.
 

bazookajoe

Well-Known Member
Whats the temp in ur bedroom? Thats ur intake air so it needs to be cooler than ur desired temp inside the tent to balance out the heat. Put a ac in ur window n keep ur door closed. Ur equipment shouldn't have a problem cooling the bulb, u just need cooler intake temps being pulled inside ur tent and over the bulb..

.02 hope this helps!
 
my bedroom temps are around 20c - 23c but in my closet they can reach up to around 30c with the light on and 19c with the light off
as for an ac the room isonly big enough for two 6'' clip on fans my intake fan and the 4 18ltr pots im growing in.
 

bazookajoe

Well-Known Member
I meant put the ac in ur br window not the tent but doesn't sound like u need it, 68f(20c) sounds like a good number for intake, BUT being as how ur intake fan is in the closet where the exhaust is dumping into.. it sounds like ur recycleing the hot air..instead of pulling the cooler fresh air actually from the bedroom into the closet and tent.
 
Try taking an empty plastic gallon milk container, handle helps, fill it with water, put the cap on tight and freeze several of them. It is the opposite of a heat-sink in a greenhouse. The cold water takes time to deice and lets off cold air that you can circulate with your fans. I even put these in the res to lower the temps.
 

Honda Cog

Active Member
Try taking an empty plastic gallon milk container, handle helps, fill it with water, put the cap on tight and freeze several of them. It is the opposite of a heat-sink in a greenhouse. The cold water takes time to deice and lets off cold air that you can circulate with your fans. I even put these in the res to lower the temps.
Awesome idea i may try this i'm also fighting rising temp issue,thanks.
 

ASMALLVOICE

Well-Known Member
Are you using one fan to do both the light and the carbon filter?

If so, you will overheat slowly but surely as you are not moving enough air through the hood to keep it cool. I use a heavy duty 120volt 140cfm axial fan through about 10" total of 6" ducting, including the 600watt light. You can pretty much touch the glass on the cooltube. I have a 4" fan on a 4x14 carbon filter, it just scrubs (recircualtes, no ducting)

So see if there is a way to seperate the two and you will have better performance from your hood setup. You pull a good 100-120 cfm thru it with as short a duct as possible and it will run much cooler.

Peace and Cool Grows

Asmallvoice
 

ASMALLVOICE

Well-Known Member
no my out take air is being dumped out of the tent and closet, but my intake air is pulling in from the closet then into my tent
So you are pulling in air that you just exhausted, or are the two seperated enough not to "short cycle" your light cooling and slowly overheat?


Peace

ASmallvoice
 
yeah my exhausted air is ducted out of the tent and out through a hole i made in the closet wall, my inline fan is drawing air from inside the closet if that
makes sense?
 

Ilovebush

Well-Known Member
This might sound a lil excessive but you can try drawing(intake) air in by drilling a hole into the wall inside the closet and placing a screen over it to eliminate any type of contaminants and leave your exhaust as is OR you can exhaust into the wall in the closet and intake from your room.
 
no i understand what your saying, the thing is i have one hole already so im not sure what to do as i have nosey visitors lol and im thinking 2 holes may standout and cause people to ask questions?
 
Top