Looking for Exhaust Advice

Alright. I have been looking through my Grow Bible and Ultimate Grow books and I have been scouring forums across the net looking for a concrete answer to my deli-ma. I started out slaning buds at 15-21 and took a short break and started growing outdoors. I have four seasons of outdoor experience under my belt and I have again taken a short hiatus from Mary Jane. (Just a little background, I have been very acquainted with MJ for about 12 years). I have decided to build a little hobby room in my garage. I worked for a contractor for a few years so it was pretty simply putting up 2" x 4" walls, insulation, and drywall. On the interior of the room I plan on putting up infared mylar. I have been out here in the southwest for a few years and in the summer it can get really hot here, in the 110's.

Room is approx. 7' x 8' x 7' High

Intake. For my air intake I was planning on just using a window mounted A/C unit. In the summer I will defitnetly need to bring in cold air and the rest of the year I figure I can run the fan to bring in fresh air. Would a 6,000 BTU A/C unit be sufficient? Would this be sufficient for air intake?

Exhaust. I plan on running 1400 W's (1 1000w and 1 400W) of light and I know I need to have vented hoods. Do I vent these separately from my main ventilation, or do I tie it in with the carbon filter? If I do run separate ventilation for the lights do I run the risk of odor leaving the room? For the main ventilation I was planning on using a 6" carbon filter and a 6" CAP Value Line blower with a rating of 435 CFM. Is the carbon filter and 435 CFM blower sufficient.

I plan on running a perpetual harvest and am going to use NFT/Aero systems to do this.

What would you do if you were in my situation? Any advice is greatly appreciated and I will give mad REP.

Thanks.

I'd say you should run the hood through the main exhaust. Basically everything that leaves that room needs to go out that one way! Secondly I'd say keep the 435 cfm fan for either another project or for circulation, more on that in a second. For a 1k light I like 700-900+cfm fan, and I'm not in the hot ass south west either! i was doing some buds once in a tightly packed residential nieghborhood, and even the smallest amount of odor would freak me out. So i ran one smaller fan (like your 435) on top of a carbon filter just on the opposite side of the room from my main exhaust. It just blew up into the room, and didnt go anywhere, but it got a lot of air through it, and moving about the room. The main fan and carbon filter, exhausted the room, and cooled the fans. For that grow room having that fan and carbon filter further conditioning the room's air, BUT only having one powerful exhaust and keeping negative air pressure in the room, made for an almost odorless grow. That was 3 lbs at a time of AK, and Bubblegum, so no small task!

I'd say go with a huge fan to exhaust, the bigger the better!!! I'd say .8 cfm/per watt of lights minimum, and exhaust and vent light with the same powerful fan.

Good luck, be safe.

That sounds like a good idea. Bringing in air with the 435 CFM fan. I actually don't have any in line fans at the moment but it is something I would consider doing. That kinda what I figured in regards to the air all moving out of the same exhuast. I apperciate your insight in regards to the larger extraction fan. I would rather spend the extra money and make sure it is done right. I probably couldn't go to big with an exhaust fan, but if I went to small I would be screwed. I also have a question regarding my 400 w MH. Is there a significant heat difference between a 250 w and 400 w MH. I plan on using the 400 w for the veg plants, but if their is a significant heat drop I might consider going with the 250 w down the line. Thanks for your advice.

I'd say yeah, my step dad was using a 250hps for a while, and they just dont have the penetration. I'm not saying you can't get insane buds from a 250w, but in comparison a 400 or larger is like "easy mode" 250s I guess have their places and purposes. Why cant you get a bigger fan? Or a big squirrel cage blower maybe? Your girls will thank you. There is a reason good fans cost more than good lights.