How to insulate sound on a 8" vortex

[rr14]

I saw a hydro video off the net and the guy had a wooden box that the fan was inside of. I previously had my fan inside a cabinet and it worked very good to cut down the constant humming of the unit. I also am using insulated duct.

Do places sell the boxes that you can hang from your roof to put your fan in to insulate sound? I'm not worried about the sound coming out of the duct, but rather the sound of the motor of the fan.

 

[Vern Equinox]

I use this for my cab setup; not fully sealed yet, as I may change my 8 inch Hurricane for the six inch model. The duct muffler was fun to make, and works really well. Keep in mind, if you don't need all the CFMs, you can get a solid-state speed controller to reduce rpms and noise.





EDIT: Here's the plans for making a cheap, effective duct muffler! Based on his site's hits, this freaking guy must think there's a helluva lot more woodworkers in the world than there actually are!

http://home.alliancecable.net/~woodworker/dcmuffler.html

 

[Sauce]

A few things that will work are:

-Foam in a housing like Vern posted in the pic.
-Insulated ducting
-Duct muffler (can be built cheaper than bought)
-Variable speed controller (aka solid state controller) for your fan. This only works though if you don't need all cfms of your fan.

 

[irie-i]

i slipped a piece of fiberglass insulation into a garbage bag and taped it nicely. i wrapped that around the fan and taped it to the fan

 

[cabanetforester]

Well

Well

I have a 6" Vortex mounted using the supplied brackets and the fan/motor is very quiet.

I can't even hear the fan over the sound of the moving air... but then again I'm partially deaf

 

[Guest]

if i made the end of the exhaust larger and larger diamter and insulated it would than get rid of the wooshing sound? like a large cone on the end of the exhaust.

 

[Sauce]

Maybe some of it but I get most of the wooshing air sound from the ducting itself because the air is hitting all the bumps and folds in the duct. If you use all insulated ducting it should cut down on most of the noise. I imagine a cone piece at the end would help a little bit though.

 

[New Holland]

I had problems with noise. Mainly the sound of the air rushing through the ducting. I switched my 6" fan and duct for a 12" fan and ducting with the 12" fan running at half the speed of the 6" I was still moving the same CFM and noise was almost non existent.