Ceiling dust cleaner

[atgcpaul]

For those of you with ceiling mounted dust cleaners, when do you use it? I've had a Jet for about 10 years and I no longer use it while I'm actually working in the shop. Doesn't seem smart to let the dust circulate around me.

If I'm sanding, I'll wear a face mask and when I leave, I'll turn it on. However, I could just as easily just let the dust settle. It's starting to feel a little obselete to me. I guess I'm in no rush to sell it since it's not really in the way.

[LCHIEN]

I have one hanging from my ceiling using a mechanical on+delay timer switch that I can dial up to 12 hours or so.
I have a DC connected to my table saw or Planer and a some shop vacs on various pieces of equipment (miter saw, drill press, band saw, Jointer). Still some dust escapes and its usually very fine dust than hangs in the air for hours before settling. Things like routing and sanding I don't even have a vac.
Running the Air filter for a while clears this from the air.

So when I go in the shop and prepare to do some cutting, I will turn on the timer for 4-5 hours (or more if I am planning to be working for a while). So I have it running even after I retire and close up the shop for the night to help clean the floating stuff from the air. Unfortunately I have enough dust around that I can't find a dustless place to point to but it does keep the air clean.
The trick of course is to let it run for a few hours and clear the air by circulating all the air.
Fortunately the power it requires is much less than the DC (about 1 Amp vs 15 Amps) so it doesn't cost all that much to run for a few hours.

The secret is that the air cleaner moves something like 750 CFM. Your shop if its a two car garage size is about 3300 cu feet. A 750 CFM air cleaner will pass a garage sized amount of air through it in 5 minutes. There's no guarantee it will move every cu ft. of air through it, but In an hour it will pass 12 garage sized air hunks through it. In 3 hours it will pass 36 garages through it, increasing the chances greatly that any airborne particles will get filtered. Of course it helps to have the Air filter centrally located so that it'll push air all around.

Provided the air particles stay suspended and the fines really do, there's about a high percentage chance in 3 or 4 hours that any given cubic inch of air will pass through the filter.
So those floating fines will be >90% removed by the filter. They won't get stirred up next time I'm in the shop.

So my plan is to let the DC/ shop vacs get the first majority of larger and smaller particles and dust right off the machine.
The remainder is sprayed onto the machine or floor and into the air whether you like it or not. THe larger stuff you sweep up. The fine stuff you want the air cleaner to get.

[cork58]

With my asthma I run mine allot. Usually go through a filter every month, works great for me.

Dan