I’ve been looking at tents and various other grow gear that I’d need for a grow, but what I’m wondering is, what’s everyone’s opinion on stepping up one size of exhaust fan, not to increase ventilation, but to move the same amount of air at a lower rpm?
I’m a computer junkie, and going with larger fans, to reduce rpm’s, is a common practice, I’m just curious if it’s recommended for growing as well?
It’s a very wise thing to do . I do it, rarely run mine at 10, (high)
With AC Infinity T6’s on my 3x3 tents I never have to go past speed 4 of 10 to stay in the proper temps. Larger fans can move more air more quietly, but we consider it more of getting the proper size fan for tent size. a 4" exhaust fan is pretty much only good for up to a 2x2, 6" fan recommended for 2x4, 3x3 or 4x4 etc…
Also important is getting a good quality fan and hard to beat AC Infinity for quality and quiet operation and great customer service.
I was planning on getting an AC, for a 2x4 or a 4x4, I can’t decide, mainly due to my back issues, watching plant care videos made me realize I couldn’t reach all the way back in a 4x4, but I’ll likely be getting either a gorilla shorty (my basement is only about 6’ tall, and the short, with the included extension is 5’7”,) if I go with a tent instead of building a grow closet/room, and they have doors on front and back, so I could have easy access to both rows.
That being the case, I was considering a 6 inch if I get a 2x4, and a 8” if I get a 4x4, so I can run them at lower speeds, and was wondering if that would be a waste and/or too much ventilation for the tent, even if turned down? Oh, also I plan on getting the controller that monitors temp and humidity, and will increase the rpm if they go above whatever set point you program in, if that makes a difference in your thoughts.
I run a ac infinity t6 in my 4x8x6ft tent and like hellraiser said it hardly gets over 4 to maintain temp and humidity and it does a pretty good job. The t4s aren’t really enough for anything over a 4x4 in my opinion as mine are always running at 6-8
I also have height clearance issues and I run the tents made for HPS bulbs which sucks but it was the tallest tent I could find for my basement. I have an extra 3-4 inches on top of my tent before ceiling so it works out ok. Only downside is I don’t care for these cheaper brands material they use as opposed to gorilla or secret Jardin with much better material. All in all my tent ain’t bad the material doesn’t change the way the bud grows and more room is better in my eyes
I have the t8 on a 4x7xi.room anything over 4 and walls crackle lol. Usually mine stays on 2 3 at highest. I’ll crank it up time to time to get the cats looking like they r about to experience a jet coming thru the ceiling lol. AC infinity for the win for sure. Super quiet compared to any fans I’ve used that are cheaper. I have a 8 inch hydro farm and that baby hums loud even turned down lower speed u hear the hum real well
I have no problem getting the job done with a 6" Exhaust fan in a 4 x 4 space. No more than medium speed which is Pretty quiet. Good luck
I had 4" AC Infinity fans in all 3 of my grow spaces when I started. I’ve since upgraded the 4 x 6 closet to an 8", and my 2 1/2 x 5 and 2 x 4 tents both got upgraded to 6". The 4" fans had no trouble keeping the temperature in check, it was the fight against humidity they were losing, lol. It’s much better now with the larger fans, and I only have to use the higher speeds when the humidity is insane!
If you buy an Ac infinity fan use Code canuck15 for 15%off 
good luck
Thanks everyone, and I’ll definitely use that code, thanks.
I’m running 4" AC Infinity exhausts in my 2x4’s. They are controlling the high temps pretty well in the veg tent (I had to switch to 6:2 lighting schedule to avoid the lights out cold swing down to or below 65F). The problem I face is that I grow in a very arid climate and trying to raise humidity is a real issue. I’ve been able to increase it from 25% (ambient) to 45% with a full-time humidifier in the tent and hanging two wet towels.
I have an 8" dimmable fan. I route 6" from 32x32-3x3-4x8. Exhaust from 4x8 8". I pull through all 3 and out big 1. At full blast the fan will suck the tents together…lol. when running the 8 in 4x8 alone i can run 30% and achieve massive negative pressure.
@JaneQP hmmm I think you on to the magic 
, lol , oh yeah I understand now why your stuff be looking good un huh !
@yoshi I learn something new every grow and watching others’ grows. Great forum here. I lurked in other forums but did not dare post because of the negativity. If I wade through their arguments, I can glean some relevant tidbits.
It’s funny how some of my tricks really do work huh ? 
I’m weird but I do have a creative mind and if I sit and think , ponder on it a bit , a light goes off ah ha , and it all snowballs from there !
Get 6" ac infinity and call it a day. Even if they were junk I would still use them because they are quiet. Turns out the hold up pretty well too. Imo would save the money on controller and get the manual speed control model “S6”. Works plenty good enough for what we’re doing.
I’m still making sense of my new system, but my 5’x10’ tent gets a 8" exhaust and a 6" supply fan, both of them triggered by my environmental controller… I might’ve been better off with two 8" (easier to balance them), but it’s not troublesome to set up.
