Dust collector exhaust noise problem

[David Sparks]

I recently got my Oneida V3000 up and running. I'm using my old 2 hp blower to suck dust from my scroll saws. I've run the exhaust pipe outside and am trying to come up with the least expensive way to reduce the outside exhaust noise. My exhaust pipe is 4" SD PVC. I'm thinking about making a muffler using more 4" pipe with a bunch of holes drilled in it running through a piece of 6" SD PVC packed with fiberglass. Do any of you have a better suggestion? Thanks in advance for your help..

[Jim O'Dell]

I guess my question is what size pipe for the exhaust does the V3000 have coming out of the unit? 4" seems very small. The transition I made for my Clear Vue accepted an 8" pipe that I wyed off to two 6" and used some 6" clothes dryer type vents for the side of the wall. Doubt that it made any difference in noise, but I couldn't find the vents in 8".
You can build a muffler. See Bill Pentz's site for information on making one, or google it and I'm sure you will find several ideas on making one. The exhaust is loud. But I'd think that if you are choking it down to a single 4" outlet, you are robbing yourself a lot of suction in the shop. Good luck! Jim.

[David Sparks]

Hi Jim,
I'm actually using the blower from my old dust collector. I'm using my V3000 with the filter that came with it. I looked at the muffler on Bill's site. I may got that route. Thanks for the information.
David

[Jim O'Dell]

Gotcha. Now I understand. No problemo, glad to help. Maybe some others will chime in on what they have built, what worked, and what didn't. Jim.

[Rod Sheridan]

I purchased a muffler for my Oneida, then I converted it to an external filter which had a built in silencer.

PM me with your e-mail address and I'll send you a photo of it.

If you lived in Canada I'd ship you the thing.......Rod.

[Leo Graywacz]

Did the Oneida filter make any difference? They told me it was a 2dB drop in noise, hardly worth it. If it was 20db it would be fantastic.

[Rod Sheridan]

The silencer did drop it about 3 dB if I remember correctly, which is a lot.

Regards, Rod.

[Chris Padilla]

dB is a logrithmic scale so dropping the sound level 2-3 dB is significant...at least to my ears. This is like the Richter Scale for earthquakes...also logrithmic: a 5 earthquake is 10 times worse than a 4 earthquake. 3 dB drop is about 50% reduction...2 dB drop is about 37% reduction.

I have the Oneida as well but I put it on before I ever fired up my DC so I have no idea how much louder it could be.

[glenn bradley]

The muffler on my cyclone is somewhat like the one you want to build. For a 7" pipe the muffler is about 15" in diameter. The path through it is 7" in diameter. This opening is surrounded by a sound absorbing foam filling the 15" diameter section. I was disappointed in the noise reduction and wondered why I had bothered. Then I heard a similar machine without a muffler the other day . . . . reasonable difference; not fantastic but definitely noticeable.

[george wilson]

I am wondering if your small 4" pipe may be causing the collector to be more noisy. This is only a guess. Have you heard similar collectors with 6" pipe? Not that any of them are quiet.

[Paul Demetropoulos]

I would think if you connected maybe an 8 foot piece of insulated flex duct and laid it out in a U shape it would cut down on the noise, cheap and easy.

aflex.jpg

[David Sparks]

First, I want to thank all of you who responded to my question. I decided to make a muffler using a 35 gal. plastic trashcan. I drilled 1 3/8" holes around the perimeter of the can about 2" from the bottom to let air escape. I put a plywood disc with a 4" hole in the center inside the can squeezed in to about 6" from the bottom. I drilled a section of 4" SD full of 1/2" holes. After cutting a 4" hole in the can's plastic lid, I glued two PVC couplings and a short piece of pipe together connecting them through the hole. I sealed this with silicone to keep rain from leaking in. I filled the can with several layers of carpet padding standing on edge. I also put a piece on the plywood disc and crammed some in around the top of the other padding to keep noise from coming through the lid. I glued the piece of SD pipe with the holes drilled in it into the inside coupling on the lid. I slid the pipe down through the hole in the plywood disc. The end of the pipe extends just a little past the bottom of the plywood. After putting the lid back on the can, I hooked up my exhaust line. When I cut my 2 hp blower on now the exhaust noise is less than the noise coming from a clothes dryer vent. I'm happy with how it worked out. Thanks again.

[Paul Demetropoulos]

Good solution David

[Neal Flatley]

A 3 dB change may represent a 50 % reduction in power, but the human ear hears things differently. It takes approximately a 10 dB change for us to perceive something as being "Twice as loud" or "Half as loud"

This is why hearing protectors with a rating of 30 dB, which represents one one thousandth of the original power, are sometimes required to protect our ears.

If we were to hear in a linear fashion, we would not have the dynamic range required to hear a wisper and then a car horn.

Neal

[John Schreiber]

First, I want to thank all of you who responded to my question. I decided to make a muffler using a 35 gal. plastic trashcan. I drilled 1 3/8" holes around the perimeter of the can about 2" from the bottom to let air escape. I put a plywood disc with a 4" hole in the center inside the can squeezed in to about 6" from the bottom. I drilled a section of 4" SD full of 1/2" holes. After cutting a 4" hole in the can's plastic lid, I glued two PVC couplings and a short piece of pipe together connecting them through the hole. I sealed this with silicone to keep rain from leaking in. I filled the can with several layers of carpet padding standing on edge. I also put a piece on the plywood disc and crammed some in around the top of the other padding to keep noise from coming through the lid. I glued the piece of SD pipe with the holes drilled in it into the inside coupling on the lid. I slid the pipe down through the hole in the plywood disc. The end of the pipe extends just a little past the bottom of the plywood. After putting the lid back on the can, I hooked up my exhaust line. When I cut my 2 hp blower on now the exhaust noise is less than the noise coming from a clothes dryer vent. I'm happy with how it worked out. Thanks again.

I think I understand what you are describing, and it's a good solution for a low price. I'm confused though as to where the dust is going. Do you have a cyclone upstream of the muffler? Does the dust blow through the muffler and out the holes at the bottom?