Grow Room Too Hot, need advice, and yes I did a search....

Bezy

Active Member
So I have been growing for over a year now with some success, but anyways onto whats important.

I have a 12'L x 4'W x8'T grow room thats attached to my house and has a door that goes outside and a door that leads into my garage, I have spent a lot of time and money on this room and this last problem I have been having is heat, and too much of it.

Where I live it gets well over 100 degrees in the summer and it has been a struggle to keep my room under that in the past, so let me get into my set up.
I have a 6500 BTU A/C window unit butted up against a open vent hole on the floor of the room, Ive thought it might be a problem that the whole ass end of the unit isnt outside of the room, but I digress.

I have a 1000w MH/HPS grow light for flowering and vegging with a Hyro Farm vented hood hooked up to a 480 cfm squirrel cage fan that vents into my garage. I also have a vent hole that brings air from my bedroom which is air conditioned, and I have used this hole to make the light hood a sealed system, but it hasnt made a difference as of late because the temps are at about 90-98 degrees right now.
I also have four separate CFL's that keep the mothers and clones going, but dont add to much to the heat problem as the room can be much cooler with the 1000w off.

Now I need to solve this problem as its killing my growth and giving me pest problems, my ideas are as follows;
- install a fan to pull air in from my air conditioned bed room
- put a bigger exhaust fan (I already have one) on my grow light, as it has a lot of piping that snakes around which Im sure is killing flow
- Make is so the a/c is vented outside properly
 

Sugarskull

Well-Known Member
I think if you got the ass end of the ac out of the room and did the fan for the light it should make a big difference. Ac units put off a lot of heat so that might be abig problem right there. Hope this helps.
 

Bezy

Active Member
Yea thats what I was thinking but the only way is how? I was going to put it in a 18 gal tote then vent the ass end to the outside, but it didnt quite fit right and I dont feel like cutting a hole in my wall because I want to keep it stealth, plus how do I drain the water off? I guess Im gonna go to Lowes and see if they have any totes big enough to fit it, and figure out something.
Also, Im using a HydroFarm vented hood (Just as good as a cool tube) with a 480 cfm fan attached to one side and it open on the other, it was completely sealed and sucking cool air from my bedroom and blowing it out to the Garage, but with one end sucking from the grow room it seems to keep temps a little lower and it helps suck air through the vent coming from my bed room.
For now I have switched from a 24hr veg cycle to a 18/6, so the light is off from noon to 6pm, the hottest hours of the day which has helped keep temps 80-85 degrees with the light on and 70-80 with the light off.
Now the only problem is to figure out why my plants in my new Hyrdo set up are drooping =(
 

desertrat

Well-Known Member
had the same problems, tried the same things, finally got it to work. for the whole story check out the last link in my signature below. for the short version - the a/c is your problem. first, you have to seal the back end so that no hot exhaust air is getting into the room. if you can't seal it, you're going to need a portable unit or a split mini system. even with sealing, your unit may be too small to cool your size room with a 1000 watt light. i took a shot at it with this calculator http://www.consumerreports.org/cro/appliances/heating-cooling-and-air/air-conditioners/sizing-worksheet/index.htm and came up with 10,000 btu's. third, the unit will be much more efficient if you can direct some of the cooled air from your house into the intakes of the a/c.
 

Bezy

Active Member
Thanks for the insight, it says I needs a 7600 BTU unit, I guess thats not too bad, I'll see how much better it is once its all sealed off. I was just always mystified because its such a small room (12x4) and I insulated the floors and ceiling well, you just have to really take into account all the heat generated by the lights I guess.
 

Black Thumb

Well-Known Member
Switch to nights and get some fresh air into the room an hour before you flip the lights on if possible.

Good luck
 

Bezy

Active Member
Well i found a simple solution and I feel pretty dumb for not thinking of it earlier. My A/C is on the floor of the room and the room is fairly tall, the ground always felt cool but near the ceiling hot (Heat rises, I know) so all I did was take a little fan I already had sitting in my garage and put it bellow one of the A/C vents and pointed it strait upward, perfecto! The Temps by my mothers and clones dropped from 90-95 to 70-75 and my flowering unit is a few degrees cooler too. Always remember, keep it simple stupid (Or stoner in our case)
 
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