Grow tent airflow

Discussion in 'First Time Marijuana Growers' started by Metalmulisha71, Aug 31, 2017.

  1. I am running 2 300 watt mars hydro led's and to my surprise there's a ton of heat coming off of them , there in a 3x3x6 grow tent with a 4" exhaust turbine style fan that will suck the sides of the tent right in if totally zipped shut , my temps with a flap open at the bottom , and lights right at the top of the tent with the carbon filter 2" away from the led fans is still getting to 80 degrees , I have no way of bringing fresh air in from the outside , anyone know what I could do to lower those temps , no money for co2 or an air conditioner

    Sent from my iPhone using Grasscity Forum
  2. The temp sound great to me and don't worry about fresh air in the grow room, your plants will be fine
  3. I think 80 degrees is pretty high , should be down around 70-75 ideally

    Sent from my iPhone using Grasscity Forum
  4. In the perfect grow maybe, but a lot of flower rooms hit 80-90 in the summer
    • Like Like x 1
  5. I think you will be ok man just don't let temp creep to much higher. I some time used to leave tent open to my ac cooled room when needed . gl man

    Sent from my N9515 using Grasscity Forum mobile app
    • Like Like x 1
  6. Chamber temp without Co2 = 75* to 78*F
    Chamber temp with Co2 = 82* to 84*F

    80*F is not a grow stopper but don't let it get any higher or you will start seeing heat stress.
    • Like Like x 3
  7. Yeah you're right...
    I was giving the chamber temp general rule of thump :thumbsup:
    • Like Like x 2
  8. You said two Mars Hydro 300's with a 4" fan - guessing that is about 170CFM and that won't be enough... I'm not familiar with Mars 300's, but I have a Mars II 700 that I run in s 2X2 X 5'3" tent. When I first bought it I already had a 4" 170CFM fan in the tent so I tried a dry run. Temps quickly went to the mid 80's before I shut it down. So I bought a 6" Can Fan Max Pro series, three speeds switchable between 290CFM, 3-something, and 420CFM. The low setting (290) keeps inside tent temps within 2 to 4 degrees of the outside-tent temps. I'm guessing partly because my room is air conditioned.
    You might try mounting the carbon filter and fan outside the tent, it may be a bit more efficient at cycling the air. And try to find a manual way to exhaust heat from your grow room - open the door, box fan, anything you can do. But mainly I think you're gonna need a bigger fan for the tent.

  9. JAKE!!! You old SOB, how ya' been, Man???? Haven't seen you on here in ages! Great to see you back. I took some time off myself, just getting back and spending a bit of time on the forums again. Hope all's well your way & life has been treating you well. I still owe you a Mountain Dew if I ever get on your side of the lake.
    Midlife, GreenGun & D Norris are all long gone, Dr. Mengle's about the only one left of the old bunch.
    Shout out & let me know how ya been?
    • Like Like x 2
  10. Pail of Ice water with a towel to wick up the water and air moving across will help a lil, but the RH will go up too.
    • Like Like x 1
  11. This post interest me mostly because I was contemplating purchasing another 450w LED for my tent in his tent is comparable in size to mine but I do not have any heat issues at all with my ventilation system with only one temp never gets above 72 degrees

    Sent from my N9515 using Grasscity Forum mobile app
  12. What up ya Old School dawg!?!?!?!?!?
    Yeah seems everyone from the old group have moved on.....
    Damn it's good to see an old friend still around!! :yay:

    I stopped growing for a while, had to move, and just now got a room setup..
    I bought 20 acres in a national forest that had an old 3bed 2bath, so I gutted it, rebuilt the rafters so I could put drywall up in the place, and the grow room was last....

    I just now got it setup and testing as I go along...

    Trying to do this grow on the cheap (as usual)..
    With the stuff I already had, this grow setup cost me $50 so far, but I need a drip system, and that's another $50, thus I'll be waiting to get the drippers... lol

    Attached Files:

    • Like Like x 1
  13. What are the red hoses that appear to be running to your lights?
  14. #17 Olde School, Sep 2, 2017
    Last edited: Sep 2, 2017
    Drip system? You not doing ebb 'n Gro anymore? You converted me from ebb n flow tables to ebb 'n gro buckets. It's a lot simpler (and works better) since I downsized everything I do to single plant grows in a 2X2 tent. With everything I'm still knocking out 8 to almost 12 oz harvests off autoflowers. Having fun & smoking the proceeds
    Really liked the water cooler system you put together for your cool tubes. I see it hooked up in the pic above, sweet setup.
    The one gripe I have about LED's (yeah, I'm trying those too) is that venting the heat from the tent is not as simple as with an HID cooltube combo. I've been toying with the idea of building a sheet metal baffle where the light sits in the middle & the baffle extends out to all four tent walls to seal out the heat. If I can seal it well enough I might be able run a traditional centrifugal fan for heat exhaust, and a separate centrifugal thru a carbon filter for odor control. But, where is the fan / filter going to sit? Would have to exhaust out the bottom of the tent, or find one with a low port on one wall. Right now, heat & odor exhaust fan runs 20 on 4 off thru the carbon flter & I suspect that's gonna burn out the carbon a lot quicker.
    Maybe it would be simpler to just sit the fan / filter in the room, outside the tent, and filter the air in the room rather than as it exhausts the tent. I did that for years when I was running flood tables & no tent & it worked pretty good. Thoughts welcomed, Bro.
    • Like Like x 2
  15. Jakester & I sometimes finish each others sentences.... it's a water cooled attachment to his cooltubes. See the sweet how-to here:
    Let's Build a Water Cooling System
    • Like Like x 2
  16. Why can't you just screw a squirrel cage blower to the top of the LED??
    Then you can vent it right out using a 6 or 8" flex duct...

    Yeah my system is a custom coco mix in 5gal buckets that's top fed using drippers set to about 5gal in 15minutes...

    Attached Files:

    • Agree Agree x 1

Share This Page