So i've done my research for a while now and i decided in about 3 months im going to start my grow, but im still VERY confused about how to set up an exhaust. I'm gonna be growing in a closet about 3x5. So if someone would be so kind as to explain to me...step by step lol what i'll need and how to set up a simple, working (of course) exhaust. PLEASEEEE!
Hi, OK here goes... I grow in a double door closet. 2x10 x8 (160cuft of air) I use 1/3 for the veg side and 2/3 for the flowering side. I use a 400watt HPS light with a cooling hood for flowering, and t-5's for veg side.
You want to be able to change the total air volume of the space in less than 5 minutes. Your volume I'm guessing is 3 x 5 x 8?, which equals 120 cubic feet of air. So a small exhuast fan that would remove a 120 cubic feet of air in 5 minutes would be around 25 - 30 cfm. I recomend going much bigger though, like maybe 2 and a half times, so maybe a 75cfm fan or bigger. Reason being is you can use a variable speed controller to adjust down the speed of the larger fan to cut down on noise. Otherwise the smaller fan has to run balls out all the time to cool or dehumidify and you have no way of controlling noise. A bigger fan is nice too for when summer comes and the room gets even hotter, as well as for the beefier construction that doesn't work as hard or wear out as quickly. The size of the fan & ducting relates to the size ducting you want to have on your air cooled HPS light hood. Usually 4 to 6 inch ducting for a closet.
You need to get an 'atmospheric controller' of some kind to run your exhuast fan automatically within a certain temp or humidity range. You'll also want to use a charcoal filter in the line somewhere. The filter can go on at the front or rear, just make sure it can handle whatever cfm fan you get.
So for my closet I use a 465cfm 6" Vortex in line fan mounted in my attic with a Can 50 carbon filter (38 special) it vents out through, (I went real big because I eventually want to vent a second smaller closet through it.) At this point though I can change out the air almost 3 times in a minute if I want, I actually run it at around 1/2 speed most of the time meaning 230 cfm are being removed a minute, still bigger than I'll ever need until the 2nd closet is on line.
The ducting goes down through my closet ceiling into the flowering side and to the hood of the 400watt cool breeze light I use. The fan is plugged into a variable speed controller, which in turn is plugged into my atmospheric controller. Additionally I have a small 2 quart dehumidifier in the space which is also plugged into the atmospheric controller. So the fan runs whenever the temp climbs over 75 degrees (most of the time) and the de-humidifier runs whenever the humidity is over 50%.
The doors on the closet aren't air tight so I don't use an intake vent but if I did I'd add an intake in the floor from the basement crawl space where the air is cool. Hope this makes a little sense and helps. I attached a few pics that hopefully will help explain a bit more.
Similarly, I also recomend using a Coleman cooler in a size that works in your space for a reservoir. Light proof, keeps things cool and dampens the sound of my pumps working, sturdy too! Large reservoirs don't go through drastic changes in short periods of time pH and TDS wise. You can go on vacation!
Lastly, I'd get Jorge Cervantes Marijuana Horticulture bible. Lots for you in there. I'll subscribe to this thread if you've got questions. Otherwise Happy Gardening! GrowIT!
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