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Thread: Harvey vs clearvue

  1. #31
    Join Date
    Jan 2010
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    Tampa Bay, FL
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    Carl:

    Which units are the numbers you are stating? AQI? PM2.5? PM10?

    That Banggood (I have one too, as well as a Dylos) displays all of them (with the largest text size being PM 2.5.)
    - “It’s not that I’m so smart, it’s just that I stay with problems longer.” – Albert Einstein
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  2. #32
    Join Date
    May 2008
    Location
    MA
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    2,000
    Quote Originally Posted by Alan Lightstone View Post
    Carl:

    Which units are the numbers you are stating? AQI? PM2.5? PM10?

    That Banggood (I have one too, as well as a Dylos) displays all of them (with the largest text size being PM 2.5.)
    This meter has an AQ mode - chart attached.

    But the numbers I am quoting are the >0.3 and > 0.5 values on the particle count mode. See pics (live at my kitchen this morning - need to air it out in here!). The larger particle size counts do not climb at all when running the equipment (shaking out dusty rags will spike it though!), and I am more interested in controlling the smaller particles.

    Net net is that although I was not able to run the side by side, the particle counts suggest the Harvey is doing a reasonable job.

    I hate to start yet another dust collection philosophical thread, but a site I found interesting was here: https://www.shophacks.com/getridofthe-dust.html#/ It was making the case that collecting at the source is key, and if you can pull that off the large volume 'brute force' method may not gain much.

    I plan to run a bunch of MDF cuts and test (just because that creates an obnoxious amount of dust particles). And I havent tried the belt sander yet. I do know the ductwork run is relatively lengthy/convoluted, and the sp values can not be where most 'general wisdom' is regarding what is 'needed'. But at the same time, it seems to be in control per this particular meter. The qualitative 'feel' that the shop isnt filing up with dust also supports this (be wary of qualitative testing! Hence the meter). The meter does only go down to ">0.3 um", but I might suggest smaller particles are more buoyant and thus pulled away with relatively lower air velocities. (although I have a 6" main, the branches are 4" - there is likely a balance of velocity vs pressure drop, and too large dia with low airflow might actually impede collection due to dropping below a min velocity - this likely plays out at the point of particle generation). Already sucked in too far to the technical debate, which I wanted to avoid.

    Interpret all this per your own personal philosophy.

    IMG_4304.jpgIMG_4303.jpgIMG_4296.jpg

  3. #33
    Join Date
    May 2008
    Location
    MA
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    2,000
    After getting the overhead guard/DC on the table saw, I ran a test to see how effective it was. Very simple test.

    The meter sits about 4ft in front of the saw on a table. With both the overhead and the under port open, the BEFORE numbers on the particle meter:
    IMG_4395 (1).jpg

    The AFTER 10 cuts of 1/2" MDF:
    IMG_4397 (1).jpg

    Effectively no change at all. I didnt even bother testing before the overhead was in place because it creates a cloud of dust when cutting the MDF with no top collection.

    Next time I will run a test with the DC turned off just as a control reference.

  4. #34
    Join Date
    May 2008
    Location
    MA
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    2,000
    This particle meter continues to be interesting. My highest ever reading today:

    image0.jpeg

    This was in my kitchen approximately 1 hour after cooking a burger on the stovetop.

    The workshop has never gotten to anything close to these values.

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