Hidden attic space 4x4 cooling advise.

Jozikins said:

The a/c you use in your 4x4 space is going to have to be big and strong enough to cool down a space that is at least 10x10. Attics are tough environments to grow in, luckily you are in a state that stays relatively comfortable all summer long. I personally love 600w lamps, and you should consider it because you have a very cramped space with very little over head room. You could accidentally burn your plants with a 1000w during the learning curve. The fact that it is only 5 ft tall means your plants cant get much taller than 2ft tall, and a 600w is a more appropriate lamp for plants of that size. 1000w lamps can grow 4-5 ft plants, but you need 1 1/2- 3 feet of of space between your lamp and your plants, usually. Air cool the living shit out of your lamp and add A/C and you will be fine. If you don't exhaust, humidity may be a problem, so think of a small exhaust fan to retrofit onto it, 4" Inline fan or a 6" duct booster would do, but I always have to recommend a real inline fan, you can put a speed control on it. You usually cannot control the speed of a duct booster.

If you are only growing 3 or 4 plants, the smell may not get strong enough to leave the attic and enter the streets, but if it is a fear for you, hydrofarm makes a little baby carbon filter for like 80 bucks. There is always DIY ways of doing it, which are fine, but I just want it done right, and I want it done the first time, so I'll pay a little extra.

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I think the smallest BTU A/C I could find was 5000BTU and could cool a 200sf area, but portable A/C's are so expensive it sucks cause Im broke right this second so it could take a month or two before I can get everything for this grow, including soil, lights, seeds, pots, insulation, plastic wrap, and so on. I dont live in a place with a comfartable summer, South Carolina has an average of 90-95degree days all summer long. Also I was told that a cool tube with a strong enough fan will keep the bulb cool enough to be able to get 8-10in away from the bulb. I was planning on hanging a 2x2 sheet of 1/4" glass from my light and about 10-12" under the light so if the plants did hit a growth spur in a 3-4 day period, they wouldn't grow into the light just into the sheet of glass. I already built a DIY carbon filter so im not worried about smell, but thanks for the advise on the inline fan instead of booster since the booster is probably loud, also good thinking about the humidity thing but if it becomes a problem luckily I have a awsome dehumidifier.

shizz said:

i built mine using only insulation no wood just glue the sheets together with spray insulation. also i would pull air from sofits threw your cool tube. i would also pull air in threw sofit and into your attics with some fans. your going to need alot of air flow. i mean alot. even with air conditioner. i dont thin it could keep up.

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Please explain how you used only insulation and not wood, what held your box together and how much did the insulation cost. THIS GOES FOR EVERYONE IF YOU KNOW WHERE THE BEST PRICES ON INLINE FANS AND PORTABLE A/C UNITS, AND ANYTHING ELSE I MIGHT NEED PLEASE POST LINKS OR TELL WHICH STORES CARRY THE PRODUCT. I prefer to buy stuff locally instead of ordering it so if you know of local place like lowes, home depot, walmart, or other places like this with good prices on stuff like white plastic, insulation, inline fans, and such please post. Anyway thanks for the advise on pulling air into cooltube from soffit and out soffit. I might be able to make my intake in the floor which would make for a huge difference in temps but the part of the attic that is hidden and closed off from the rest of the attic is over my front porch and I think thats why it stays slightly cooler in that part of the attic. My point is I have speakers installed in the ceiling of my front porch but you cant see the speakers when you on the porch just the wire mesh thats over them so I was thinking maybe if I could leave the speaker hooked up but pull it out of the hole where its installed maybe I could run my intake duct where the speaker is and no one could see it from the front porch because of the wire screen that is over the speaker. There are multiple speakers on the front porch so i dont think anyone will notice that one of them sounds a little quieter than normal I could probably take the speaker out completely and no one would notice.

shizz said:

a 1000 watt no way id go with 2 250watt. in cool tubes spaced apart, this well give light at differnt angels and to lower branchs. and less heat. i would also runn my lights at nite when its cooler.

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2- 250w would be more expensive than the 600w and I dont want to have to pay any extra that I dont have to but thanks for the advise. I was planning on running lights at night, for veg im planning on running lights from 6pm-12pm which is 18/6 and flower I will run lights from 8pm-8am

IgrowUgrow said:

Wow thanks for the advise I would try the verticle grow but I plan on growing them to roughly 18" tall and flip to flower the White Rhino strain I plan on growing is a very short and bushy compact plant that is said to finish under a meter if flowered at 16-18" and yeild 2-3 ounces if grown properly under good lighting. I want to put like 10-12 plants in there in 3l pots and just have 10-12 big main colas, and the next grow after that I might try scrog and see if I yeild better I dont know thanks for the info tho. +rep

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There is no way if you a vegging to 18 inches that you will fit 10-12 plants in a 4x4 space using 3l pots. Regardless of what strain you are growing, during flowering phase expect the plant to double minimum in size. Then you have to take into account the height of the pot plus a good 12 inches minimum between the 600w and the top of the canopy.

Now if you are working with 5 ft, why not grow the plants until they are about 9-12 inches tall and then put into flower because they will grow over two feet. Also with regards to a fan pulling air through the cooltube you will need a fan that is moving over 200 cfm at the very least and even then I doubt it will cool the grow cab if you are expecting temperatures to rise above 90 degrees.

chinoholmes said:

There is no way if you a vegging to 18 inches that you will fit 10-12 plants in a 4x4 space using 3l pots. Regardless of what strain you are growing, during flowering phase expect the plant to double minimum in size. Then you have to take into account the height of the pot plus a good 12 inches minimum between the 600w and the top of the canopy.

Now if you are working with 5 ft, why not grow the plants until they are about 9-12 inches tall and then put into flower because they will grow over two feet. Also with regards to a fan pulling air through the cooltube you will need a fan that is moving over 200 cfm at the very least and even then I doubt it will cool the grow cab if you are expecting temperatures to rise above 90 degrees.

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I understand what you mean thanks, 11-12" would prob be a better hight to veg, because during that first two weeks of flower they stretch out and I might end up running out of room, but if I did run out of room I would just tie them down and grow the stem around the outside of the pot like I am doing now with my CFL grow. Thanks I need to know what CFM fan I need to run through the cool tube, now that you say 200CFM at he least, I will get a 250CFM just to make sure it keeps the bulb cool. I see you are a newer member here and dont have much rep but Im going to give you the benefit of the doubt, thanks for the info. Oh yea does radioshack or anywhere sell those giant 6"CPU fans that run like 250CFM.

I think its a great idea as for the ac have you looked into a window unit and put a pan under it to catch condensation it wont work the best do to high attic temps but it would be something and you can get them for really cheep. and for those big cpu fans check tiger direct.

window unit with no window, wouldnt the hot air just blow right out the back of the A/C unit instead of out the window.

IgrowUgrow said:

Thats a great Idea but I live with roomates that dont want to run the air, so the air only gets run on really hot days and that means I wouldnt have a constant supply of cold air going into the grow room all of the time just on really hot days, and it doesnt have to be that hot outside for the attic to reach 105-110 degrees. I have no idea what you are talking about with bug filter and such why are you talking about carbon filters, I already have a DIY carbon filter. Im planning on growing a low odor strain anyway.

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I'm talking about a bug filter to dampen the amount of cool air going INTO the grow room. So that it doesn't greatly effect the rest of the air you and your roommates enjoy. Sorry for the confusion.

I live in the south and have a make shift bug filter over the intake to my attic grow. Never open the bug filter to check if it's working. That is how I let all the bugs stuck to it inside the grow room. And they will eat them bitches up.

I havent added up the prices on this stuff yet, but I know it wont be cheap its going to be way more than what I thought it would be like 800-1000dollars for all this stuff and Im probably forgetting some things. If there is anything else I forgot thats important please remind me
I havent added up the prices on this stuff yet, but I know it wont be cheap its going to be way more than what I thought it would be like 800-1000dollars for all this stuff and Im probably forgetting some things. If there is anything else I forgot thats important please remind me.


600w HPS/MH - 6" cooltube reflector and ballast (euro) complete package
large surge supressor
PH meter and PH up and Down
30 gallons of distilled water
2-12" oscallating fan
15ft drop cord
fox farms potting soil/perlite
light hangers
white plastic 100ft
wall insulation 80sqr foot
2-250+cfm fans
2x2ft 1/4in thick sheet of glass
10- 8ft 2x4
2lbs bag of 2" self sealing roofing screws
2-10ft 6" A/C ducting
mini portable A/C unite 5000BTU
12-2gallon pots
2-digital times
10ft rubber seal for door frame.

attics are a bitch! hot as hell in summer and cold in winter. i'd spend lotsa money on insulation!

ClosetSafe said:

I'm talking about a bug filter to dampen the amount of cool air going INTO the grow room. So that it doesn't greatly effect the rest of the air you and your roommates enjoy. Sorry for the confusion.

I live in the south and have a make shift bug filter over the intake to my attic grow. Never open the bug filter to check if it's working. That is how I let all the bugs stuck to it inside the grow room. And they will eat them bitches up.

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Man I kinda understand and kinda dont, I understand what a bug filter is now and the purpose but what does it have to do with the cool air going into my grow room and how could it affect the air me and roomates share.

Im sorry I could be a RA-tard I dont know.lol

I dont mind it gettng hot but I dont want to spend all this money and then it get to got for me to grow in which Im sure if I can get a portable mini A/C with the built in exaust hose I could just exaust out the box into the big part of the attic. Those potable A/C dehumidify as they cool the air and they have tanks that need to be emptied, some of them have a hookup that you can run to a bigger res so you would only have to empty it once every 2weeks or so, and some have a evaperative feature where they reuse the water they get in the air to cool the air or something like that. So im hopin I can find a cheap, quiet, and compact portable A/C

1000 BTU Air Conditioner will cool 40-50 sq ft to answer your question. Personally id find a better place to grow where temps arnt so excessive.

[420]Haze;5557472 said:

1000 BTU Air Conditioner will cool 40-50 sq ft to answer your question. Personally id find a better place to grow where temps arnt so excessive.

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I wish I had a better place to grow but this attic space is the most stealthy thing Ive seen, It is completely hidden and if I could keep the temps right up there I could possibly get a year or two long perpetual harvest going which is something Ive dreamed of since I even got into growing pot. If a 1000btu A/C will cool 50sf it should cool my 20sf grow box.

Oh yea anyone here ever heard of skywalker OG kush, I got some the other day frm a friend and I usually get all my tree through my brother but this shit was dank. I get jack herrer, blue dream, trainwreck, granddaddy purp, and a bunch of other shit but this skywalker OG was the best I have ever seen, smelled, smoked, and tasted by far.

dude i dont know jack about growing but i've been a builder all my life. if uou do a really good job insulating that space it will take very little to control the heat. possibly use rigid insulation for your walls mayby nothing else. seal it up and run your ac or intake cool air from outside just sayin

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

IMO, I would no recommend growing in an attic for multiple reasons. Attics are a magnet for critters, squirrels, birds, mice, rats, spiders, and many other critters. Regardless if your attic has an air conditioner inside the room, the humidity is going to be extremely high. I assure you if you are fighting temperatures of 130 degrees that your humidity levels will be high, regardless if the heat is minimized. For the price you pay for an air conditioner you can get a grow tent like a secret jardin 120 [4x4x7ft] which creates a perfect environment for your grow, which could be kept in a different room. I have one in my bedroom, and you cannot smell a thing outside the tent because of my carbon filter. I dunno man, attics are attics, and I i personally feel you should avoid using it as a grow space.

Regardless, I am subbed, and I do indeed wish to follow you my brother, I always wish for a success grow +rep for the idea and good luck to you mang

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.