Jim Haddar
Well-Known Member
I want to buy an exhaust fan for this vent. The fabric tube is 8 inches diameter. Would a 4-inch or 6-inch fan work okay or should I pay a few more bucks for an 8-inch? No jokes about titles of sex tapes, please.
Basic question about tent exhausts
- Thread starter Jim Haddar
- Start date
Dontjudgeme
Well-Known Member
All depends on the cfm. Any exhaust can be retrofitted regardless of the tents exhaust hole size.
Work ok for what? We know nothing about your setup. What size tent? Lighting? Temp and humidity?
Smaller fan will fit in a large hole, but not vice versa. Most tents (if not all of them) have ropes to pull and tighten the hole around the fan.
What is your tent size? In my opinion larger is always better, you can run it on lower speed, it's quieter, and you have that extra airflow if needed.
I run a 6'' fan in a 2x2x6 tent. The only problem is that bigger carbon filters are more expensive so you do the math.
What is your tent size? In my opinion larger is always better, you can run it on lower speed, it's quieter, and you have that extra airflow if needed.
I run a 6'' fan in a 2x2x6 tent. The only problem is that bigger carbon filters are more expensive so you do the math.
Jim Haddar
Well-Known Member
PopAndSonGrows
Well-Known Member
4 inch works fine in a 4x4 (it's what i use) but a 6 inch would be better IMO. 8 inch for a 4x4 is unnecessarily large
ProPheT 216
Well-Known Member
6 inch b better, once you add a filter you drop half or more of your cfm
FirstCavApache64
Well-Known Member
Also depends on the heat your generating with your light and how long of a run you're making with the exhaust ducting. I wouldn't use a 4" in a 4*4 unless budget was a big issue if you're going to be running a carbon filter. Get a 6" that's adjustable and you won't have to run it wide open constantly and have really loud exhaust noise like a 4" struggling to keep up.
PopAndSonGrows
Well-Known Member
Not only am i using a 4" inline fan and ducting in a 4x4, i also have it teed off to exhaust a 2x2 and it works " just fine". It has to run at 100% at all times, but it does work fairly well. A 6 inch is already on-hand to replace it but I've been doing this going on 18 months. Both tents also have decent negative pressure as well.
Lenin1917
Well-Known Member
Depends on the size of the tent, but a 6in 400ish cfm fan is pretty much perfect for a 4x4, if you run it max and duct outside your golden. That’s your rh managed(depending on plant count and pot size), that’s enough air exchange to seriously limit the potential for pm or mold spores to colonize, it’s just all around a good move.
FirstCavApache64
Well-Known Member
Based on what I've read you want to exchange the air volume between every minute to two minutes at a minimum. A 4*4 is 106 cu ft so while a 6" 400 cfm fan seems like overkill, being able to run it reduced and also having the ability to overcome clogged up carbon filters and long runs of exhaust with multiple bends is nice. I have an AC Infinity 6" fan that never has to go above about 6 on a scale of 1-8 for power setting to control the temps and humidity. Usually it's at 4-5 which is pretty quiet. Nothing wrong with a 4" fan at all but I just like having a bigger motor and not having to push it hard all the time, I figure it's easier on the equipment as well.
Lenin1917
Well-Known Member
Ideally an indoor grow environment should be capable of 8 exchanges per minute, unfortunately that’s not practical or even possible for most of us and in all but extreme cases(like my dumbass putting 75 gallons of soil in an 8x4) more than a bit of overkill. 1 exchange per minute is adequate but more is better. My 8in at max(760cfm) fan barely keeps up with my dumbass decision to try bigger pots, I have a 12in fan(1060cfm) too, but my filter is 8in and blowing an unfiltered flower tents exhaust out my dryer vent seems like an even worse idea
FirstCavApache64
Well-Known Member
I don't know, I'd like the smell if I was your neighbor but yeah, probably not the safest idea for operational security 
If the price difference doesn't bother you, get an 8'' to make sure you'll never have problems. Something like AC Infinity and run it on low speed, it will be nice and quiet. You can put any ducting length with bends and it will be fine. Even if you run it on higher speed i don't think there is such thing as too much CFM?
And maybe someday you decide to upgrade the tent to 5x5 for example, the bigger fan will come in handy.
And you can use a smaller carbon filter if you run the fan on lower speed. For example i have a 6'' fan running on low speed with a 5'' carbon filter and reduction attachment. Not the ideal setup but it works fine.
And maybe someday you decide to upgrade the tent to 5x5 for example, the bigger fan will come in handy.
And you can use a smaller carbon filter if you run the fan on lower speed. For example i have a 6'' fan running on low speed with a 5'' carbon filter and reduction attachment. Not the ideal setup but it works fine.