I have a newer double wide mobile home and I have a closet 4' x 6' x 8' ceiling. I am going to have a 1000 HPS and a 400 MH with sealed reflectors. I am leaning toward the 6" duct over the 8" because I want to run the duct from under the home(2ft high crawl space that is concrete block perimeter) y off, go into the lights, then another Y and back down under the home exiting close to an outside vent. I will use insulated duct going from the lights back down since I am taking heat downward and will probably either install the fan just after the lights or just below the floor on the exit side. I may be able to exit the duct in the ceiling at corner IF there is enough vent on the over-hang of the roof but I am not counting on this being enough room to exit this amount of air. I plan on using the C.A.P. Xtreme Greenhouse Contoller that will run everything and has Fuzzy Logic for Co2 monitoring/control. The area I dont have figured out yet is how to work the heating issue. I cannot hook up a window a/c because that is too noisy. At this point the only idea I have come up with is an 8" or 10", maybe 12" exhaust that will pull air from top of the room down under the home and have a fresh air vent also from under the home since this air will be cold in the winter time. If I am remembering correctly Co2 is heavy so I need a fan to circulate air in the room. I thought I might be able to run like 50' of duct (not insulated) under the home and just circulate it do cool it and then back into the room, and also have a de humidifier hook to the C.A.P controller. Not sure how this will work, if it will cool enough or not but the nice part if it will is that I would be circulationg the Co2 as well. I would appreciate any other ideas on this setup and I would love to see pics of some nice rooms as well.
Sounds like you have a good plan in motion and you know exactly what you want. So you're off to a good start! One thing to keep in mind, is that duct fans lose power the longer the duct is, or the more turns it has. Only 90 degree turn will cut the CFM in half. This makes it difficult to push the air long distances unless you have a lot of duct booster fans or one hell of a blower. I just set up air-cooled hood in a sealed room with CO2 and am faced with similar challenges of keeping humidity down and keeping the temperature stable. Dehumidifiers and air conditioners are bulky and noisy, and I don't exactly need yet another draw on my circuit. It seems the best solution is fans or louvers connected to a hygrometer/thermometer and setting the exhaust at the top of the room to let the heat and moisture escape, yet keep the heavy CO2 floating at the bottom. My garden is a panda-plastic room within another room. The panda plastic room has little ventillation except what is exchanged by the gap in my duct, and my intake fans are on the external room which helps keep the external room cold and thereby cooling the plastic room. Okay, back to my bowl...
Hey DokiDoki I was checkin out your pics of your growroom remodel and it looks pretty nice. I am thinking if I could run like an 8, 10, or 12 inch duct that would pull air from the ceiling area then down and under the house, using two or three fans, I think two would do it. Then by circulating this air as slow as possible giving it time to cool (make duct as thin as possible so the cool temps can drop my temperature) then enter the room at the floor. This way the whole system is closed and the Co2 would not be lost except for having an exhaust that could exit when needed to keep the negative pressure in check. I will just have to get this installed and get it running to see what works best.
Sounds like a good plan. You might look into getting a blower for active air. I found the duct fans were not quite enough to pull the air through, even with a slight boost. Found on on ebay for about $80 that looks perfect for my needs. duct blower items - Get great deals on Home Garden, Business Industrial items on eBay.com! I am now finding that humidity is a problem with a sealed room. During off hours I have to vent out the room with a fan and pull all the moisture out, b/c when the lights are on it generates a little heat and humidity. Reeally hoping the new blower will help with that, but I may end up making some small intake and outtake in the ceiling if only to fight humidity and stale air. Good luck!
If a guy is running C02 then I am thinking a dehumidifier should do the trick. I have also been doing a lot of reading and if I can or do deciede on an a/c for the room it will take moisture out of the air. I may start out just by exhausting air out and pulling fresh air in and let the controller put the Co2 level back where it needs to be. It might not be too bad that way and then I can look at improvements. I do not mean to offend anyone by pointing to a Thread/Journal from another site but you just have to see this setup. This truly is what we all dream of having https://www.icmag.com/ic/showthread.php?t=154567 I totally love this!! This one has some very good knowledge for us all. https://www.icmag.com/ic/showthread.php?t=90287
Always something, huh? I may have to get a dehumidfier myself. I hate adding more electrical devices though. Ideally, I want to get it to where I can actually remove a fan. ha ha. And what a grow!! That guy really knows his shit, but damn he clearly spent a lot of money to build it so pro. Wish I had some electrician and carpenter friends! Thanks for the link!