Bathroom Extractor Duct Noise Fluting etc..

[rideforever]

Was looking at attaching a rectangular section duct to a bathroom extractor about 3m to get it to an external wall.
Is it likely it will make noise fluting or anything?
Any good solutions like rubber sleeve or inserting rubber sections to break it up?
Anyone ever done anything like this?
Yes it will be covered by a box at the end.

 

[vxxbcks]

Is this in attic space?

 

[rideforever]

Is this in attic space?

No it's a victorian conversion so that pipe would run along the ceiling of a bedroom before it reaches the outside wall. I just don't know what to expect if the pipe is put in there attached to the wall (looking at a low profile rectangular section one) ... and a mdf box put over it, is it going to hum when the fan is on and be noisy in the bedroom, is it better to put some rubber around it ? Any experiences?

 

[vxxbcks]

connect the fan with a short length of flexi and maybe pad the box with at least 1" of fiberous material around the duct to act an an absorber.

 

[rideforever]

connect the fan with a short length of flexi and maybe pad the box with at least 1" of fiberous material around the duct to act an an absorber.

thanks