Hidden attic space 4x4 cooling advise.

You could make your cool tube a closed loop cooling system, then have the rest of box be sealed tight. Intake from your house and exhaust right into your attic ( assuming you have vents in roof/ gable. The majority of the heat from the bulb will never get the chance to heat your box up. With a setup like this the smallest ac you can find would be overkill. Just insulate like you described and you will be left with a 4x4 frig in your attic.

shizz said:

the stuff i us is called great stuff its a spray foam that fills holes around pipes. the insulation is blue 10 bucks a sheet. i painted the inside white you cant spray paint it. youll save money with 2x 250 over a 1000 watt on eletric and airconditonering cause theres no way you can runn a 1000 without air. hell you might have to have it for the 250.. just trying to save TIME. I HAVE MINE IN MY BASEMENT 4X4X10 WITH A 400WATT. ITS TO HOTT. RUNS AROUND 95. I HAD A 1000 WATT IT WAS 110 AND I HAD AIR. THE AIR RAN NONE STOP.

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Thanks for the info man, I have been wondering what would be better to use 2-250 or 1-600w I guess you would get better area coverage with two lights Ill check up on the lumens and see what the difference is.

longroot said:

Probably shouldnt go with hydro with temps that warm. Warm water and roots dont go well together.

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I would get water chillers or something if I ever did run hydro, I thank you for the good advise though since I have heard before not to grow hydro in the heat.

minigrows said:

You could make your cool tube a closed loop cooling system, then have the rest of box be sealed tight. Intake from your house and exhaust right into your attic ( assuming you have vents in roof/ gable. The majority of the heat from the bulb will never get the chance to heat your box up. With a setup like this the smallest ac you can find would be overkill. Just insulate like you described and you will be left with a 4x4 frig in your attic.

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I dont have vents in the attic just soffits, I will need some kind of cooling like a 1000btu mini portable. Also I dont have a way to make the intake come from inside the house because the area I will be growing in is over my front porch.

I use a 600w in a 3x3x5 (ish) in an attic how ever it isn't too hot up there. Check out my grow journal, a 600w is good for the space... But my temps are at 77 degrees when the light is on, 60 when it isn't. So theres no doubt if you had a small air con unit you'd have no issues with a 600w and might be able to use a 1000w if you have a big ass fan on your cooltube.

Otherwise, 400w cooltubed + maybe 6500k cfls... Sealed up and with a co2 system in hope that they can bear the heat...

chinoholmes said:

I use a 600w in a 3x3x5 (ish) in an attic how ever it isn't too hot up there. Check out my grow journal, a 600w is good for the space... But my temps are at 77 degrees when the light is on, 60 when it isn't. So theres no doubt if you had a small air con unit you'd have no issues with a 600w and might be able to use a 1000w if you have a big ass fan on your cooltube.

Otherwise, 400w cooltubed + maybe 6500k cfls... Sealed up and with a co2 system in hope that they can bear the heat...

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Ok I have a couple of questions for you then.

1. What part of the country are you from are your summers really hot, because my summers reach the 100s here.
2. Are you using a small A/C unit
3. Does your attic have good ventilation, like fans on each end of attic. Because my attic doesnt.
4. If your not running a A/C how is it possible to get 77 degree temps with lights on and 60 lights off during the summer, unless you live in canada or something.

IgrowUgrow said:

Ok I have a couple of questions for you then.

1. What part of the country are you from are your summers really hot, because my summers reach the 100s here.
2. Are you using a small A/C unit
3. Does your attic have good ventilation, like fans on each end of attic. Because my attic doesnt.
4. If your not running a A/C how is it possible to get 77 degree temps with lights on and 60 lights off during the summer, unless you live in canada or something.

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I live in a place with quite cold summers in comparison to you (around 80 degrees, I run the lights at night in the summer), I do not run any AC unit at all. No ventilation in my attic. So I honestly cannot give you 100% trustworthy knowledge as I am not in your climate.

Running the light on at night with the A/C unit on during the day might be your best option. How hot does it get at night? If the temperatures can be maintained below 90 degrees with the light on using just a cooltube and no A/C at night then sealing up your box with co2 and having the a/c running during the day might solve your potential heat problems.

But as I have said, I have no experience with the temperatures you are talking about.

Since you are spending money on A/C go ahead an insulate the grow box between two layers of plastic, So you don't waste any money on electricity. Efficiency is the idea. Oversized is better than undersized, just check out the minimum power use and maximum power use, so you can figure out how much it will cost in the end. Remember, if things get 140 in your attic, you are going to need a fucking kick ass A/C to handle that with a 600w light/heat source above the plants. I recommend 3 gal pots over 2 gal pots. 2 gal pots will give you a good harvest, but not the great harvest and density I get from 3.5 gal buckets