Hey guys i have a 710 cfm inline fan and im trying to set up a future grow. Ive found out im going to need to run my ducting about 35 feet per fan, also with major amounts of curves in the ducting. I realize that curves in the ducting isnt ideal, but the only grow tent that i can find that would reduce the amount of turns is the Hydrohut Grow Tent. But i dont like where the intake ports are on that tent, it will be blowing air right on my plants instead of on my floor. (I cant use the mesh intake screens. I like using an intake fan much more) So mainly my question is, can i run 35+ feet of ducting with an 8" 710cfm inline fan? Or should i buy a couple of duct boosters? I need to get a good cfm match for a carbon filter, so im pretty lost here.
As long as you are not "reducing size" and you have natural curves, then I don't think you should incur a problem.
What are the cfm ratings of the carbon filter your looking at? Unless they are very close to the rating of your fan, you should be fine. 710 is a beast. Just saying that thing on full blast is a pretty powerful fan. IMO If I was worried about the CFM rating of my fan, I'd ditch the intake fan, but that's just me as I've never used one. I run a single 4in 175 CFM through a scrubber and about 20+ feet of ducting total from a 22x30x60 grow box without issue. My indoor grow is much smaller than yours though.
How large of a space will you actually be growing in? 710 cfm is pretty hefty and can work for expelling air in a pretty large space. The problem is only minimal with the distance you wanna run but still could be more ideal. Your main problem will be in the curves and angles of the ducting. Obviously straight with no bend is most ideal. 30 degree curve can cut up to 20% of the air transmission. 45 degree curve can cut up to 40% of the air transmission. 90 degree curve can cut up to 60% of the air transmission. So depending on how many major curves you got, you may wanna spend the extra 40-50 bucks a piece on extra in line duct fans especially around any 90 degree curves just to push things along. Also if you think your room will run at high temps you dont wanna skimp on proper ventilation. Hope this helps. Good luck.
I dont think ill have to reduce the duct sizing, thanks for the help The CFM rating of the filter is 750cfm, its a very close number to the fan so i think im ok. And i just love the intake fan lol, i have used the mesh screens on my tent before, but i put an intake filter on my intake fan and it helps keep hairs, dust, mold, ect out of my grow space. And i really like how light tight it is with the screens closed. But then again i have a cat lol! But Im happy to see that someone else has to run 20+ feet of ducting without an issue. I didnt know these fans could push air that far glad they can though!!! Its actually a fairly small box, right now the 710cfm fan is working in a 4x4 tent, but i want to upgrade to a 5x5. Its alot of air movement, but i dont use any A/C units, or air cooled reflectors. The ducting will most likely be shaped like a big "S". So if i did need the booster fans, would i put them on the curves of the ducting? They would be gradual turns, not major kinks in the ducting . Thanks for those numbers man! I hope i can make this work out
I guess if I were you I would try to place the fans in areas so it helps pull the air around corners over trying to push past the corners. In my opinion, id say as long as the "s" curves are gradual, placing the boosters at point of the curve will be fine and should take care of the issue. On another note. Just out of curiosity... how come you prefer an intake fan over the tent intake screens and negative pressure alone?
Cool, thanks man. And theres a few reasons i like to use an intake fan. I like them because i have a cat, and she sheds A LOT. So i want to keep her hair out of my buds. Also things like dust, mold, and spider mites. Having the vents closed also helps with light leaks, i want to put a veg tent right beside a flower tent, so i really need both tents to be 100 percent light proof Also an intake fan really helps with how much stress is put on the fan motor, at least in my opinion. I feel like your asking too much out of the fan when its working that hard, for 24 hours a day, months at a time. Its alot of work for the fan But the fans motor does get warm when the fan is on, without an intake fan being on aswell. But honestly its just my preference, i dont see too many people using an intake fan.
Sounds like you put a lot of thought into this. I like how you think ahead instead of wait until its too late. Well man I hope you get it dialled in. Keep me up to date with things. Peace