Hypothetical Attic Grow Room

Looking to move out the closet - no jokes please.

If I were to build a 8 X 8 X 8 grow room in the attic (SE USA), what would be more economical? Pull cool air from existing central air system and house, or put small portable A/C in room? Exhaust and/or ducting from both out through roof vents. The Sharp portable A/C looks pretty good at around $400.

Pulling all that cooler air from the central air and house would drive that electrical bill up as that air would have to be replaced. Portables aren't that efficient, but with less ducting and it being purposefully deployed, it may be cheaper (cost of A/C unit excluded).

Obviously, need to insulate the hell out it either way. Attic has vents, but with summer coming on, 120+ degrees not out the question on ambient in attic.

Room would be split flower/vege with lights out in afternoon. But even at night ambient attic temp are, uh, through the roof.

Thoughts, guesses, or experience appreciated.

get a window ac unit..it will pull both fresh and cool air into room. u still might have to put an inline fan on your light depending on how strong it is

Remember one thing....the cycling of your a/c unit will be dependent on where the t-stat is placed. Your house may get satisfied but the room in the attic will be hot as hell unles you manage to get a return duct back from the room to the vicinity of the t-stat.

I think I'd opt for the a/c unit assuming it's NOT a through-the-wall or window style unit. Your attic temps will be too hot to pass the air across the condenser coil and expect efficient operation. Make sure it's a small split system (indoor coil and outdoor coil). Mitsubishi makes a small system called "Mr. Slim" which has a remote condenser. However...a 9500btu unit is about 1k...a little pricy.

....or, you ventillate the hell out of your attic.....or, you use a window unit that pokes through the wall to the outside of the home. Do not use a window unit in an attic (dumping the hot air from the room in the attic)and expect it to work.

I would go with the Portable unit if you have the money, and just incorporate its exhaust with your ventillation for the room. Those units can easily handle the space, and can create and manage an ideal climate for the room. Some good ones have dehumidifiers and heat systems with filtration as well. Check out Home Depot, thats where I located mine.

what the best hydro setup for the attic? I was thinking DWC HELP!