Results 1 to 11 of 11

Thread: Noise reduction for exterior vent for dust collector

  1. #1
    Join Date
    Mar 2016
    Location
    Pretoria, South Africa
    Posts
    8

    Noise reduction for exterior vent for dust collector

    Hello,

    Need some advice. Just converted my old 3HP twin bag dust collector to a Bill Pentz inspired cyclone system. Put up ducting and I'm mostly happy with performance. My unexpected problem manifested with the vent from the cyclone going outside. I have one of those gravity flaps on my garage exterior with a PVC pipe through the brick wall. The plan was to vent the fine dust outside as I don't really have access to high quality filters and it's considerably cheaper.

    However, all the noise from the motor carries outside and it's actually louder outside the garage than inside. My vent faces my neighbours and it's definitely too loud when the DC is running. I don't really have another option for vent location. My garage is insulated and the noise from inside is... still tolerable.

    So the way I see it, I have two options.

    1) Get the best kind of filter available here. Same as this one. Importing a clearvue wynn filter isn't an option at this point. I can then jury rig this up somehow to the cyclone exhaust.
    2) Try and muffle the sound with one or more duct silencers. After some research I think I can take a page out of the HVAC book and try build some type of duct silencer. Like this and/or like this. For this I would probably get larger diameter ducting hose and maybe even insulate it?

    I'm already way over budget and neither option is cheap. I'd prefer to still be able to vent outside as the filtration option doesn't really perform as well as I'd hoped when setting out for this project. I just don't know if the muffler will even work, or if it'll restrict airflow too much.

    Any thoughts?

  2. #2
    Join Date
    Oct 2006
    Location
    Bloomington, IL
    Posts
    5,730
    In-line Mufflers dont work very well.

    A couple long sweep 90s will get the sound back into your shed.
    Glad its my shop I am responsible for - I only have to make me happy.

  3. #3
    Join Date
    Nov 2017
    Location
    Upstate NY
    Posts
    124
    Quote Originally Posted by Mike Heidrick View Post
    In-line Mufflers dont work very well.
    Agreed. I have a canister filter from Oneida that has an internal one which is supposed to reduce the noise 3-6db, and it frankly does little in that regard.
    A couple long sweep 90s will get the sound back into your shed.
    To exhaust the fines into the shop? Can you explain?

  4. #4
    Through the roof?

  5. #5
    Join Date
    Oct 2005
    Location
    Pasadino, CA
    Posts
    808
    I vented my Oneida to the outside a few years ago. Incredible Upgrade.
    Let me know if you want my old filters.
    oneida.jpg

  6. #6
    Join Date
    Jun 2017
    Location
    Saskatoon, Saskatchewan, Canada
    Posts
    413
    Your second "this" is probably the way to go. If your neighbours can't see the exhaust and muffler (behind trees or fence) then making it from weather proof plywood and lining it will be enough. If they can see it then you may have to make it match the building. Having the exhaust opening near the ground will be better than high up. You'll want a critter screen over that opening too.

    There is more information on the Woodwork Forums in Australia, Hand Tools and Machinery section, under Dust Extraction. I won't put the link up as I am not sure if it is allowed.

  7. #7
    Join Date
    Mar 2003
    Location
    SE PA - Central Bucks County
    Posts
    44,546
    You can partially mitigate directly transmitted sound from the machine out the vent be making sure it doesn't follow a straight path outside. Since you mention using the "flapper" type outlet, it sounds like you are providing a straight path for sound transmission. Put a nice bend on that vent downward toward the ground and see if that helps...this is in addition to any in-line muffle that you might consider.

    This is exactly the same issue as exists for folks who vent back to their shops from a sound deadened closet for their DC...the return must be "bent" and take an indirect path. My return to the shop provides for two 90 bends and is up-sized to account for the extra restriction that the bends create so that air flow isn't impinged.
    --

    The most expensive tool is the one you buy "cheaply" and often...

  8. #8
    Join Date
    Mar 2016
    Location
    Pretoria, South Africa
    Posts
    8
    Thanks all for the tips.

    I'll definitely add in a few bends.

    @Mike Hollingsworth appreciate it, but Californee is a long way from the ****hole I call home

    @Peter thanks I'll look for it. Critters aren't the problem. Too many snakes around for that to ever become a problem.

    @Jim ok so bends, muffling, up-sized ducting. Got it. Thanks.

  9. MTMWood recently upgraded his dust collection and put a silencer on his outdoor exhaust that might help. He did a video about it here:

    https://www.youtube.com/watch?v=cvPzRdd5EBU

  10. #10
    Join Date
    Sep 2016
    Location
    Modesto, CA, USA
    Posts
    1,180
    Ask around about big trucks/bulldozers and what they use for air filters. People here in the USA use the truck air filters because they are cheaper then the official wood dust filters. I would be surprised if you do not have bigger and better truck filters then most of the USA.
    Maybe you could get a few used ones to try from a shop. Also look at all the nice molded rubber air fittings/ducting that could be adapted for your use. I used to use an Audi air intake duct to conenect my shop vac to my shaper
    Bill D.
    Modesto, CA USA

    A quick google search found this about truck filters.

    http://lumberjocks.com/topics/237697
    Last edited by Bill Dufour; 01-14-2018 at 7:40 PM.

  11. #11
    Join Date
    Sep 2016
    Location
    Modesto, CA, USA
    Posts
    1,180
    One idea I read about for a gas engine is to run the exhaust down into the ground into a large barrel then a vent pipe up out of the ground.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •