Help: how loud are 4" inline fans?

[dark horse]

I've never seen one in person before and I was wondering just how loud they are. If you put one in your attic and are separated by a ceiling or wall, I'm trying to get an idea of how loud it would be? Like, would it be too loud to sleep? Would the sound be detectable throughout your house?

 

[Gelado`]

Depends on your fan, how you install it and how thick your walls and ceilings are, as well as how much noise you can take when you sleep! My 4" when dialed up to 75% is about as loud as a window air conditioner.

 

[Chunkypigs]

don't kid yourself, if you need quiet, say like to stay out of jail quiet, buy a quality 8" or larger and dial it down. most 4" and 6" fans are like tiny jet engines under load.

the type of motor determines if you can slow it with a cheap " speedster" or router unit or if you need a variac like sunleaves all plastic windtunnel fans.

the blowers from a used furnace are strong, quiet, and cheap if you mount them in mdf box.

use bungees to hang your fans and filter for max stealth.

 

[Snow Crash]

I agree with Gelado, depends on the fan. If you are looking for maximum quiet then...

Elicent Inline fan
Insulated metallic ducting
Phresh Silencer (possibly 1 for each side of the fan)
Titan Mercury 4

This is the quietest inline fan I am aware of with insulation to dampen the noise of the air through the ducting. The silencer will really knock down the rest of the noise and the speed controller only runs the fan as strong/loud as it has to based on a thermostat control. With all this gear you'd be lucky to hear the thing standing right next to it.

For what it is worth my 12" oscillating fan makes more noise than my 6" Elicent on medium with a Phresh silencer. I sleep about 6 feet from mine and don't even notice it behind a sliding closet door.

 

[Jnugg]

They're not that loud,but they aren't silent either.The trick is to use oversized and insulated ducting.Oversized ducting allows the air to move more freely,and insulated ducting cuts down on the noise of the air wooshing around in the ducting.Use smooth rather than rigid/flex duct right before and after the fan if possible,as rigid/flex duct cuts down on airflow efficiency.

 

[Desert Hydro]

insulated ducting ftw. also put fan in rubbermade with foam liner and cut holes for ducting in/out. problem solved. makes them quiet as they can possibly be. cardboard box with foam roll works well too. DIY and save

 

[Jnugg]

insulated ducting ftw. also put fan in rubbermade with foam liner and cut holes for ducting in/out. problem solved. makes them quiet as they can possibly be. cardboard box with foam roll works well too. DIY and save

Scratch the flimsy plastic rubbermaid tub and build a fan box out of MDF (Medium Density Fiberboard) or OSB and line with acoustic foam ir fill with expanding foam...way better at noise reduction then some flimsy plastic box.Also hang the fan/fanbox from joists in the attic with with those rubber/elastic cords...can't think of the proper name right now...to cut down/out any unwanted vibrations.

 

[Gelado`]

I grow in a tent and my scrubber hangs from the supports...the noise is manageable in an urban environment, but you can definitely tell when it's on!

 

[Desert Hydro]

youre going under the assumption that we are all closet bob villa apprentices lol. i make my own shit from wood but most people on here dont so rubbermades and cardboard works fine for the rest of us

 

[Jnugg]

I'm not assuming anything,simply stating facts so you shouldn't assume that I'm assuming...after all the saying is don't assume because when you do you make an ass out of u and me...

 

[jkahndb0]

I have an ActiveAir 4" fan and without a duct muffler its pretty frickin loud.... (even with speed control)...

I made a cheap duct muffler using egg crate foam and just rolled the foam into a circle and duct taped it to the exhaust port and now I can't hear it in the next room...

Its connected with duct tape at the bottom and then I wrapped it with masking tape so it would keep its shape...