Some help with heat/humidity?

Discussion in 'First Time Marijuana Growers' started by munkyblew, Aug 11, 2011.

  1. My heat is stuck at 80-90 and my humidity is stuck at 30-40. I have three clones that I bought at about 7 inches each and i've had them for about three days. My setup is in my closet with the door open and an ac unit pointed at the open door, theres a bucket inside with a rag thats hanging out and water, the light is a 400W hps lamp hung 18 inches above the plants, and I have a fan blowing air across the light bulb and out through a hole in the reflective shit i have hung up on all the walls. help?
  2. A/C units will lower your humidty, thats how they work in fact, they cool the air by taking moisture from it. Do you have a fresh air intake anywhere? It's best to have your grow room exhausting to the outside and drawing air from the outside.
  3. I think you need some way to exhaust that hot air out of the room all together. If you can do that it should get your heat down, as well as your humidity up. These lights dry the crap out of the air by themselves, the a/c only adds to the effect.
  4. If AC units dry up the air, how should i get cool air to my plants? my apartment is on the second floor and doesn't have air conditioning, and I live in the bay area of california, which is currently having a heat wave :/ leaving the window open only lets in more hot air.
  5. intake and exhaust
  6. #8 abrooks71, Aug 11, 2011
    Last edited by a moderator: Aug 11, 2011
    If its a portable airconditioner (which I am assuming it is) it should have a duct that allows you to vent it to the outside. If you have ever felt an A/C unit that is running (the type that sit in your window with the ass end sticking out side) you will notice they get very hot. If you arent venting the heat that the A/C unit creates outside then you are pissing in the wind. For every unit of cool aor the A/C unit produces it creates a equal amount of heat.
  7. it is a portable, but it doesn't sit in the window, it sits on the floor, and the hot air duct is in fact duct taped to the window so the hot air is leaving the room. besides the hot air leaving, and other air coming in through the small opening in the window that i have to leave open to feed the hot air duct outside, there is no air getting into or leaving the room- i keep the door closed at all times. i've tried leaving a window open on the other side of the room, in the hopes that hot air would leave through the hot air duct and fresh air would be pulled in because of the displacement, but that didn't work either.
  8. also, the air conditioner temperature reading for the room is 76 degrees, but five feet away, with no walls in between, where the plants are, the temperature reading is 86 degrees, even with the air conditioner pointed directly at the plants. will a more enclosed system allow for better temperature control, or will it make my problem worse? should i position the fan that's supposed to move the air around the lamp differently?
  9. #11 Mixted, Aug 11, 2011
    Last edited by a moderator: Aug 11, 2011
    I run a very similar system on a slightly larger scale, without any problem. so a couple of questions for you.

    On your portable unit are there slight gaps around the exhaust hose?
    Mine has two tabs that you insert the exhaust hose into and turn. It was very inefficient and blew hot air into the room. I sealed mine with silicon to stop the heat from escaping.

    How and where are you exhausting your air that cools the light?
    I found that if you move that air into the room outside of your closet it raises the ambient temp of the outside room which makes it harder for your ac to cool the room.

    How many BTU's is the AC and how large is the room that contains the closet? A 10,000 BTU AC says it cools a room that is 350SQFT, I found that to be bullshit especially when you essentially have a 400W heater in your closet cools more like 100SQFT

    What is the lowest temp setting on your AC unit?
    My AC unit reads that the temp in the room is 77 when in actuality it was more like 85 I simply turned the AC temp down to 70 which keeps the entire room @ 78

    How well is the seal around the exhaust in the window?
    If you have gaps that is still letting in heat from outside it is a problem.

    I am just guessing that the fan blowing on your lights is not exhausted properly, I highly recommend a sealed fixture or a cool tube that will allow you to properly vent that excess heat out of both the closet and the exterior room.
  10. My windows aren't very well sealed off, the tube that carries out the hot air is pretty secure, and you're right, i'm venting the heat from the light out of the closet. i dont really have a way to direct that air anywhere else, would it work if i got an ice pack and had the air blow sort of onto that? the lowest temperature setting on the ac is 62, which only brings the room down to about 80 or so, probably because of the leaks in the window. its difficult to seal it off properly because i can't pop the screen out. I live on the second floor and it needs to be removed from the outside. I now have a second AC unit, which is the window kind and is getting the temperature down to about 84 (it was at 96 when i got home today), but it's sitting on the floor because it's not small enough to fit in the window and the hot air is venting into the rest of my apartment. This is basically just a terrible apartment to grow in- no ac, second floor, in the bay area, right next to a corrougated (sp?) iron carport thing.
  11. Yeah you have to get that window sealed and everything exhausted properly. The ice thing I don't think will work as it will end up melting then evaporating adding humidity to your room. It might be in your best interest to build something on the inside of that window that will separate the back of the window ac unit from the inside of your room and that will allow you to run exhaust hoses. I would build something like this. If you can't seal it from the outside do it on the inside.

    I would build a stand and box that would allow your window unit to sit in it, this box will attach to the window creating a better seal for the AC Exhaust then place holes for your lighting exhaust and portable AC exhaust hose. the pic shows it from the top but you could place your PAC exhaust hose anywhere behind the window AC. This would help make sure that all the exhaust goes out the window and not back into the room and cause min to no damage to the apartment. Also it would completely block light coming into the room helping with the ambient temps. When placing the window unit in the stand be sure to leave the intake vents inside the room. This is not the best way to combat heat but it will work in a pinch. Also this setup will pull air from the rest of the house into the bedroom under door jams and the like.

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