I didn't post when I first read your question, but I too thought if you were
working in your shop during cooler/hotter temps you'd be loosing all of your
heat/cool air. If you live in a humid area (as I do in KY), you'd also be
increasing your humidity in you shop. I've a concrete floor and I've had
reason to vent my garage before (to remove some potetially bad fumes) and my
floor began sweating pretty heavily (not to mention some of the humidity
that settled on my tools). I think you'd be much better off building a means
of returning your clean air back to your shop. Grandad built a DC that
pulled all his dust/chips outside the shop and then returned the cleaned air
back to the shop. He lost a small amount of heat during the winter since the
air was being moved outside, but not to the extent that he was pulling huge
amounts of cold air into the shop.
The heat loss or cool air loss might not be a big concern to you, but the
humidity (if it exists) should be.

Just my thoughts,
JD

--
He that will make a good use of any part
of his life must allow a large portion of it
to recreation.
- John Locke

"Old Guy" wrote in message
...
Hi,

I don't have a dust collector, and I do have a dusty shop, so I'm sure
not an expert.

It sounds like you are doing everything right, so you should have only
limited dust. A DC and an ambient filter should give you a lot of
improvement. Clearly not enuf.

I've got an Trend facemask, and love it! Wonderful invention, simple,
and yet really effective. My friend was busy burning up a Dremel tool
when he was working with me (it was smokin) and I didn't even smell it
until I took off the mask.

Where is your dust coming from? From most machines, a good connection
to a DC should get most of it. Is your DC working properly with enuf
pressure drop and volume to collect the dust at the source? And,
with a lathe, it seems to be impossible to catch all the dust that it
generates.

It's a lot easier to trap the dust at it's source than try to deal
with all the air in the shop. If you exhaust all the dusty air from
your shop, you will be exhausting all your shop heat/cooling and you
will be working at outside temperatures. A good ventilation system
should completely exhaust the volume of your shop about 6 or seven
times an hour, IIRC.

24 x 32 x 8 x 7/60 equals 760 cfm of air to move, plus allowances for
fan efficiency and static pressure when you are sizing the fan.

My shop is 12 x 24, and I find that very little dust from my lathe at
one end travels to my bench at the other. Would you be ahead to
separate the dusty parts with a partition (or just a curtain) and
exhaust the he!! out of that area, and not worry about the rest? At
least you'd need a smaller exhaust fan. If you put the dust producing
area under negative pressure, you'd keep the dust from flowing to the
rest of the shop.

Sorry didn't answer your questions directly, but that's as much as I
know. There have to be smarter people than me out there.

OIld Guy



On May 2, 7:28 pm, wrote:
I'm concerned about the dust hazard in my shop and am trying to make
my shop more dust-proof and have done the following:
- Built a cyclone dc.
- Built a ambient dust collector to filter the dust floating in the
air.
- Just bought a Trend Airshield Pro to protect my face/lungs.

Now, I am wanting to exhaust as much dust to the outside of my shop as
possible. I searched the Internet for information on exhaust fans
similar to the ones used by sawmills, but they are expensive and
large. I'm also thinking about venting the dust/chips from my cyclone
dc outside. My shop is 24x32x8 high and in the country, so dust
discharged outside shouldn't be a problem. I may make a collection box
outside to collect the dust/chips if I go that route.

My questions:
1. Can I build a exhaust fan unit to discharge dusty air from my shop
to the outside? If so, how large a fan and does it have to be a slow-
speed fan? Or will a gable vent fan work?
2. Is it O.K. To do away with the collection bin located below the
cyclone? And do away with the filters? And just have everything go
outside?

Rob