Very helpful. I have a bathroom extractor fan with an irritating whining noise which I thought was down to worn bearings. Powered it up on the bench: quiet. And restricting either the air coming in or out by half reduces the whine to zero. So from your video, there appears to be a mismatch between the size of the outside grill which is too large for the fan.
Nice. Thanks for the feedback. Sounds like if you can find a way to restrict the flow a bit when it's installed the noise might permanently go away then
@@dadlifediydoityourselflike2293 Investigating it further, I think I have a quarter wavelength acoustic resonator after doing some calculations where the outside grille reflects some of the sound energy.
Thanks for the info. I was using a 3 inch pipe instead of 4 because that what was there. Installed a Panasonic whisper but it’s just a loud. I will change to 4 inch pipe and hope it helps.
Just to add to this nice video that the first 10 feet from the fan to the outside should be straight. As possible
Very helpful. I have a bathroom extractor fan with an irritating whining noise which I thought was down to worn bearings. Powered it up on the bench: quiet. And restricting either the air coming in or out by half reduces the whine to zero. So from your video, there appears to be a mismatch between the size of the outside grill which is too large for the fan.
Nice. Thanks for the feedback. Sounds like if you can find a way to restrict the flow a bit when it's installed the noise might permanently go away then
@@dadlifediydoityourselflike2293 Investigating it further, I think I have a quarter wavelength acoustic resonator after doing some calculations where the outside grille reflects some of the sound energy.
Thanks for the info. I was using a 3 inch pipe instead of 4 because that what was there. Installed a Panasonic whisper but it’s just a loud. I will change to 4 inch pipe and hope it helps.
Good luck. 3" is ok for 50cfm but 4" for 90-100cfm. There are code charts available online showing max cfm for various duct diameters
I would think Panasonic would say using a 4 inch is better and would decrease the sound