Please help- Exhaust fan 4” or 6”

[Hammer53]

Robc if you are growing in small bathroom I believe it will be noisy, I'm in a spare bedroom. Good luck to yah I think you can do this just might have to experiment a little

[Hammer53]

RobC Yes am using carbon scrubber, but I have a situation that enables me to vent.into the attic. So nobody.knows but me lol. And very little scent.in lung room. (Until I open the tent) and still not much smell

[RobC]

Nice. Are you using a carbon filter? If so is effectively scrubbing the smell?

[RobC]

I see, thanks for the reference. These AC Infinity are supposed to be the quietest ones which is why I chose it, I need stealth as in the sound can’t get out of that small bathroom tent is in. Guess ill put it in and test it

[Tersky]

For reference, i have a 400ish cfm fan on low and it can drown out a knock at the front door if i am in the same room as the tent. It isnt unmanageable on low, but on max, they reeeeaaaaal loud. The tent wont block the sound that much but may muffle it a tad. It all depends on whether you want to be more stealthy and be able to hear decently in the same room or if that is not an issue.

[Hammer53]

I've upgraded from a blurple to a QB

[Hammer53]

Hi RobC and welcome aboard. I did the same thing, ordered wrong set up
I have 3x3x6 tent with 4" fan and filter, and oscillating fan. Am going to get 6" fan and filter, but so far no issues, and it's been 9 months.
But then I'm stuck with 4" fan ( might use it in closet that I dry my harvest in)

I wanted.a 6" fan all along. I'd rather have more if needed, and wouldn't have to run on high. Although I've seldom run this one high.

[RobC]

You are right, I’m worried I might have to run it at max but don’t know how loud it will be from inside the tent

[RobC]

Sounds good, only worry then is if it will be stealthy smell wise

[RobC]

Thanks! If you have no issues why are you getting a 6”? What light are you using?

[grouchyoldman]

Oval ducting is a good idea Poppa. Thanks. I have experience in most of the trades, but I'm an HVAC novice.

[Poppa]

grouchyoldman Could you use oval ducting like this https://www.homedepot.com/p/Speedi-P...O-06/202907169 or is it a joists to close issue over height of joist issue?

[grouchyoldman]

Do any of you know if there is CFM loss if a 6" fan is exhausted through a 4" duct? I have a framing issue that makes 6" difficult.

[Tersky]

Depending on light setup and ambient temps (which you indicate are not high) you probably will be fine. Since i live in the south, temps an humidity require a little more airflow but as long as temps and humidity are ok it should be fine to be just under the recommended CFM.

That said, I recommend getting a fan that is more than you need as fans on high tend to be loud. Having a higher cfm fan allows you to run at lower speeds decreasing sound made by fans, if that is a thing you care about.

[Hammer53]

Hi RobC and welcome aboard. I did the same thing, ordered wrong set up
I have 3x3x6 tent with 4" fan and filter, and oscillating fan. Am going to get 6" fan and filter, but so far no issues, and it's been 9 months.
But then I'm stuck with 4" fan ( might use it in closet that I dry my harvest in)