[XsublimeX]

Im working on building a growroom in an attic, ive never really built a serious grow although ive done small scale cab grows in a dresser with CFLs and numerous outdoor runs. Im not a total noob but I certainly have alot to learn.
If anyones followed any of my posts( not sure how u can with the size of this place , WOW, its fuckin huge) im working thru some of my issues here, residential electricity isnt something im real familiar with, but im on the rite track now i think.

Anyways im well aware theres about a million places better than attic to use, but it WILL be stealth as can be and its the only space i have.
Its gonna get hot up there, hot as hell, so im doing everything i can to counteract that. My plan is to install false A/C vents and draw cooled air from the house, into a fairly airtight, very well insulated "tunnel" roughly 8x15, but its the peak of the house and theres a large area of the floor i can use, so its an odd shaped space to say the least.
Im not going to be using all the space i frame up but im building one time, not adding on a bunch. Ill also be installing a gable fan in the attic in a vain attempt to cool the air around my "tunnel", i doubt that will make alot of difference, buts its easy to do so w/e.
Im really hoping i can avoid adding a seperate A/C unit but im not sure what ill be able to get away with. Im not planning on growing anything for a bit so i have plenty of time to get everything rite. Im recording daily in and out temps to see what im working against, its possible ill only be able to grow in the fall, winter, spring and skip the summer heat.
Without writing a whole book Ill attempt to explain what im planning on building, and eventually get to my question. Im thinking im going to frame up some prefab walls with 2x4s and make them so they fit in place with each, and evntually screw them in place, like im framing walls for a big house but just little tiny ones. Before i get the walls in place im going to insulate the hell outta them, thats the whole point of prefab walls, totally insulated. Im gonna use some rigid foam insulation on both sides of the wood frame work, its easy work with and seal up tight and has great insulating ability per inch, im in a cramped space so i cant just wrap fiberglass around my tunnel, and i hate that horrid shit.
My questions are, should i add extra insulation to the dead airspace i create with my "foam board sandwich" , it seems like i should to me, but maybe total dead air will insulate better that fiberglass or foam.
And does anyone have any "breakthru" materials that can insulate better per inch than what lowes has. Most of the spray foams just way to high and ill be way overbudget by the time im finished anyways

I know my post long, boring, lacks pics, and is kinna technical for ur average poster. It probably also seems like i have it all lined out, and i think i do, im just lookin for other to chime in.
If u need more info please ask or if im just stoned as shit and make no sense ill try to clarify

[ChaosCatalunya]

Polystyrene boards work very well built up into Igloos, spray foam may be quick to spray, but is hell to clean up afterwards.... The bigger the space you have, fundamentally the bigger the area for the heat to disperse, so make it as big as you can. I managed to run all through Summer in the UK with 3 x 1000W in a loft, extraction duct spigot on hoods, air taken straight from the hottest point before it gets to heat up the whole place.

Sounds like you are going along the right path already, avoid fibreglass if you can, it always ends up floating around in the air....

Good luck

I think the IR reflective material is what you're really after. It looks a bit like a thing of bubble wrap surrounded on both sides by Mylar. Reflects 99% of heat radiation so it's fairly efficient. This can be found at the hardware store with the rest of the insulation products. Add a little foam in and you can seal up that room pretty well.

Intaking from your house is a good idea in my opinion because the air temps can be much lower than outside. Unfortunately I just don't think/know if that'll be enough. I think the doubt in that area will lead you to purchasing an in window style AC unit. I would plan on spending $250 to $300 on a good hearty 10,000 BTU+ unit.

The other option is to just vent the grow area like crazy, at least once a minute and perhaps once every 30 seconds. Get yourself a nice 10" fan that does several hundred CFM and your grow room will stay within a couple degrees of the intake temperature. As long as your intake air is below optimal for growing then you should be able to combat the heat that way as well.

[XsublimeX]

Originally Posted by ChaosCatalunya

Polystyrene boards work very well built up into Igloos, spray foam may be quick to spray, but is hell to clean up afterwards.... The bigger the space you have, fundamentally the bigger the area for the heat to disperse, so make it as big as you can. I managed to run all through Summer in the UK with 3 x 1000W in a loft, extraction duct spigot on hoods, air taken straight from the hottest point before it gets to heat up the whole place.

Sounds like you are going along the right path already, avoid fibreglass if you can, it always ends up floating around in the air....

Good luck

yea im gonna run cool tubes in closed loop curcuit so im not lettin in much heat plus im gonna start with CMH lights as they are supposed to be cooler to run

When u say "The bigger the space you have, fundamentally the bigger the area for the heat to disperse, so make it as big as you can." Do u mean the dead air space i mentioned in my first post?
Im leaning towards just polystyrene/polyiso panels around 2x4s sealed up really well. Im just wondering if it will be enough but ill just have to wait and see.

Fuck fiberglass, ive floored over about 200 sq. feet of blown in insulation and its just the most horrid shit on earth. i fell like a god damn cactus
Thanks for the input

[XsublimeX]

Originally Posted by 2Lazy

I think the IR reflective material is what you're really after. It looks a bit like a thing of bubble wrap surrounded on both sides by Mylar. Reflects 99% of heat radiation so it's fairly efficient. This can be found at the hardware store with the rest of the insulation products. Add a little foam in and you can seal up that room pretty well.

Intaking from your house is a good idea in my opinion because the air temps can be much lower than outside. Unfortunately I just don't think/know if that'll be enough. I think the doubt in that area will lead you to purchasing an in window style AC unit. I would plan on spending $250 to $300 on a good hearty 10,000 BTU+ unit.

The other option is to just vent the grow area like crazy, at least once a minute and perhaps once every 30 seconds. Get yourself a nice 10" fan that does several hundred CFM and your grow room will stay within a couple degrees of the intake temperature. As long as your intake air is below optimal for growing then you should be able to combat the heat that way as well.

Im installin Ir material today im really hoping its gonna make all the difference in the world but i doubt it will.
Theres no way to install a window unit outside, i cant cut a window in the attic and im not comfortable installing it on the wall of my grow becuase of the condensation it will create, atleast at this point im not concidering a window unit as an option but we shall see.

Im defenatly thinking more like venting like crazy, if im pullin 70 degree air thru my tunnel and its insulated well enough then in theory i should be ok, again thats why im building now and not planning on poppin beans til the summer "test period" is over

[ChaosCatalunya]

Originally Posted by XsublimeX

yea im gonna run cool tubes in closed loop curcuit so im not lettin in much heat plus im gonna start with CMH lights as they are supposed to be cooler to run

When u say "The bigger the space you have, fundamentally the bigger the area for the heat to disperse, so make it as big as you can." Do u mean the dead air space i mentioned in my first post?
Im leaning towards just polystyrene/polyiso panels around 2x4s sealed up really well. Im just wondering if it will be enough but ill just have to wait and see.

Fuck fiberglass, ive floored over about 200 sq. feet of blown in insulation and its just the most horrid shit on earth. i fell like a god damn cactus
Thanks for the input

hi XsublimeX

I just meant make the insulated loft growroom as big as possible, was not referring to the space behind the joists. Do the whole loft too, I would not leave part of it uninsulated, it could look really dodgy on FLIR ...

[JACKtheREFFER]

my 2 cents ... the Additional A/C is your best bet ... a large 14,000 BTU Window unit will be more then sufficient.. If you build the grow space solid and air tight the A/C unit should plop right in ... then if you choose can build a box around the A/C to directlly vent its exhausting air .... i would also look for units that dont drain condensing water.. Besides if it is that hot there wont be much anyways .... good luck to ya in your adventures in growing !!!

[Snagglepuss]

Insulation is cheap and easy to work with ,best of all ..it can be torn down in a matter of minutes..If your doing a large area make sure your a/c is big enough ..

[XsublimeX]

Originally Posted by Snagglepuss

Insulation is cheap and easy to work with ,best of all ..it can be torn down in a matter of minutes..If your doing a large area make sure your a/c is big enough ..

so if im lookin at the 4th pic right u have a single layer of rigid insulation for a "house to grow in, is that in ur attic? and whats the r value on that insulation. The reason i ask is what im planning is way more complex, not becuaes i wann be THAT anal i just dont wanna be burnin up in the summer, or a major signature on FLIR ( altho im just not sure how many police dept. could afford to run them) Hell if i could do this with one layer im way overthinking and over doing this.

[Justin_Credible]

Originally Posted by XsublimeX

yea im gonna run cool tubes in closed loop curcuit so im not lettin in much heat plus im gonna start with CMH lights as they are supposed to be cooler to run

When u say "The bigger the space you have, fundamentally the bigger the area for the heat to disperse, so make it as big as you can." Do u mean the dead air space i mentioned in my first post?

Do you live in too hot a climate so you could just run carbon filters and air in/air out? That is the best way I have found to reg temp/humidity. Unless, during a heat wave...