Inline Fan Noise Reducer

I got a 8" inline connected to my carbon filter and it's pretty loud even with a speed control. What's a good solution to reduce this noise?

Wrap some tick foam around the fan. Foam will absorb vibrations which lowers noise output.

ThaMagnificent said:

I got a 8" inline connected to my carbon filter and it's pretty loud even with a speed control. What's a good solution to reduce this noise?

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Is it noisy with the ducting disconnected? If it isn't then you can make a muffler or buy a muffler, because the noise is caused by air turbulence in the ducting.

If it's still noisy with the ducting disconnected, then it's the fan. You can build a box around the fan and line it with foam, then hang that box with bungee cords and it will be pretty close to "silent" even running full speed. If you don't want to build a box, you can still hang the fan with bungee cords. Longer bungee cords lessen vibration transmission, you'd have to hang your carbon filter with them as well. Just bungee cords will still cut down noise a lot.

If you're concerned about neighbors hearing your fan, the longer the ducting length to the exhaust point the less actual fan noise makes it through the ducting. After 20' or so it sounds like a normal window ac unit, if you can even hear it at all.

Sell crap metal fan, buy a silent plastic fan.

It's a hurricane fan

They sell mufflers for the blowers. Section of metal tube lined with neoprene fingers. Never used one.

I have a 8" fan and it's installed in the attic. Carbon filter connected directly to the blower. Attached to a board and placed on top about 3" of foam. No vibration to the rafters.

If it had to be inside the room, I'd build a box big enough to hold the blower. Drill an outlet and inlet in two sides of the container. Suspend the blower by rope or surround it with padding. Old clothes, foam, packing peanuts. That should cut noise by at least 50%. Most the noise is the suction rush in the inlet duct. Get insulated duct or wrap it.

I got acoustic hose which is essentially insulation wrapped round the hose with a bigger hose (maybe 2" bigger) around that. You could make it yourself but it made my rhino RVK fan almost silent.

You can also use insulted duct to reduce noise. Fan noise contains a lot of high frequencies, which are easy to control. Just simply adding a short piece of regular flexible duct will be way less loud than when the ends are open.

Definitely get a fan speed controller. Hopefully you're not planning on running the fan full on all the time. Slowing the fan speed will drastically reduce noise.

Someone earlier posted that you should wrap the fan in a foam pad. Don't do this! You will overheat your fan for sure! The majority of the noise is from the wind anyways, not necessarily the fan motor.

JDMase said:

I got acoustic hose which is essentially insulation wrapped round the hose with a bigger hose (maybe 2" bigger) around that. You could make it yourself but it made my rhino RVK fan almost silent.

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You can buy an 8' long duct sleeve at HD for less than $10. This is mine...

We built a box for an inline fan and wrapped it in insulation and hung it without bungee cords and it vibrates a lot its not loud but you can feel it for sure. I'm going to replace it with a hurricane fan and buy a silencer for 50 bucks and call it a wrap I hope