Warning: Overheating!

Discussion in 'Grow Room Design/Setup' started by jdskyguy, Jan 8, 2013.

  1. Gday GC!

    JDSkyGuy here with a problem that hopefully you masters of growing can help a newbie out with (Albeit a newbie who has read alot).

    Problem: The temp in my tent gets up to 95 degrees, way too hot for growing from what I've read.

    Tent - 2X4X4 - It's in a dark long closet. Pretty tight fit.
    Lights - A) 2 foot 4 bulb T5 -( though one socket is broken making 3 bulbs) B) 2 43w CFLs under clamp domes C) 2 43w CLFs hanging free.
    Ventilation - Carbon filter (roughly 3 feet), a 6 inch in line fan (250 CFM), and duct work leading to exhaust hole (4 inch duct but ghettoed to fit on air tight).

    So the quick story. I bought this setup from someone and it came with a 4 inch inline fan. There was hardly any air coming out of the exhaust duct work, but when you stuck your hand right next to the exhaust of the inline fan, a sizeable amount of air was being pushed through. I went out and bought a 6 inch fan, same thing. As you will see in the pictures, the duct work seems to have some tiny holes in it, but would that affect the air flow that much? Is there any other reason why after only 3 feet of duct I would lose so much air flow?

    I have received my seeds from the Attitude today, so I'm ready to get this solved and get to growing!

    Attached Files:

  2. the duct need to be scealed if you have plenty of holes air will escape and then you loose some power , but with a 6 inch blower, what is the kind of the fan ? if its only a fan then normal its not enough strong, if its a blower 6 inch, then it sould be very enough..
    with this way, also maybe looks like if you have a 6 inch blower then maybe its too strong, its at the bottom where cold air is it so air dosent seem to have the time to interact with the top of the tent and then hot air is staying in the top. look this
    you should put your blower right in the top,, ar the very top in the tent, find a way to do this im pretty sure it will solve your problem.
    there is no way a 6 inch blower cant cold a tent like this with only cfl and t5
  3. Thanks Newthumbgreen for your insight. I have since done work to the tent.

    I have installed a new intake fan, it was the old 4 inch inline that came with the tent. I had to cut a hole on the only available side, right next to the exhaust. I think the fan blows hard and far enough away not to interfere with exhaust but what do I know.

    The exhaust doesn't feel like it's pulling enough out though, not near what it should. I have sealed all other holes and vent in the tent, as to avoid positive pressure.

    Exhaust: 6 inch inline fan, 250 CFM. Carbon filter attached running through 4 inch duct work about 3 feet straight up.
    Intake: 4 inch inline fan, 80 CFM. Low to ground to introduce cooler air.
    Tent: 1.5X4x4
    Lights: 4 43W CFL and 3 HO 2 foot T5 bulbs.

    Problem: Temps get well into 90s. Since installing intake fans, temps get to roughly 90. I think I feel cool air trying to get in, which is good for the negative pressure right?

    Attached Files:

  4. i know its a bit hard to work out with a tent, but the thng is the exhaust need to be at very top end, to pull hot air out, the air intake, passive or with a fan, need to be at bottom, in the base of the tent where cold air come from, that your only way if your already in a closet, then in a tent, not a lot of choice theree, your exhaust try to pull air from the ¸neg pressuge witch is good yeah, but you still want a be lower than that sorry man, if your humidity is really really low, like 10-20 %, and your on a low budget you can buy a humidificator than will help to upper humidity and you will gain about 3 degrees, more humidity is high less hot is it also, well it help. otherwise maybe you need to put your tent at another place or just buy something to cool your air lol there is many possibilities. but your on the good way
  5. I think it may just be a simple matter of hanging your carbon filter at the TOP of the tent. Hot air rises and the filter, being at the bottom of the tent, does not pull any hot air out. The other suggestion I have is to make sure your entire exhaust run is sealed. That way, you won't get any leakage on the way out. Leaks may also allow stinky air to get out of the tent btw, so seal carefully.
    I personally wouldn't put any fans on intakes, just leave them passive. Negative pressure is created when the EXHAUST fan has enough pull to create an incoming "vacuum" of sorts. Blowing air into the tent creates negative pressure OUTSIDE your tent.
    Hopefully this information helps since I'm not 100% positive on any aspect of growing, but I've read quite a bit ;)
  6. I'm trying to make out your fan but can't quite figure out what type it is. If it is one of those inline duct booster fans then it may be contributing to your cooling issues. They tend to rely on fan velocity to move air but do not take particularly well to restrictions like the one created when attempting to draw air through a carbon filter. Just the same I've seen folks use them with varying degrees of success. You may need a fan with a little more "torque" so that it can continue to draw sufficient amounts of air to evacuate air and heat from your tent. As "newgreenthumb" stated there should be no way a 6 inch fan cannot evacuate your tent. The one caveat I would place would be if it were one of those booster fans it may not be able to overcome the restriction created by the filter.
    Also the suggestion to find a way to hang your filter in the top of your tent is solid advice.
  7. Yea you need a real inline fan not one of those boosters..you're prob getting like 50cfm with that filter on there

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