Marcus Lisle on tue 5 jul 05
My wife and I are setting up a ceramic studio in a space which is about 425 square feet. It is
too small to have a seperate glaze mixing room, so we are trying to figure out what the best
solution would be for venting dusts from glaze and plaster mixing, so they do not become
airborne in our workspace for hours.
We cannot simply put an exhaust fan in the window because we are in an artist loft
condominium building with neighbors' windows and the main entrance nearby, so we need
the duct to vent up through the roof, like our L&L Vent-Sure system will be doing for our two
kilns. Based on the research we have done, a local exhaust ventilation (LEV) system which
pulls the dusts out near the source of the dust making is the best type of system.
We have looked through Bailey, Axner, Sheffield Pottery catalogs, and the only options there
seem to be spray booths which are not quite the right solution, or Vent-A-Kiln circular Kiln
hoods. Can anyone who has a Vent-A-Kiln hood guesstimate whether they have enough
power to draw the dusts up and out? This is still not ideal since it would be pulling dusts up
past our faces/respirators.
We have also checked around Grainger's web site, but they do not seem to have local exhaust
ventilation systems that would work for this application either. We are surprised we have not
been able to find pre-fabricated systems for this purpose on the web, or in the marketplace.
This must be a common concern for potters around the world, so if anyone has found a
satisfactory solution, we would be grateful to learn from your experience.
Thank you in advance,
Marc Lisle and Christine Cavalier
Snail Scott on wed 6 jul 05
At 11:31 PM 7/5/2005 -0400, you wrote:
>...we are trying to figure out what the best
>solution would be for venting dusts from glaze and plaster mixing...Can
anyone who has a Vent-A-Kiln hood guesstimate whether they have enough
>power to draw the dusts up and out? This is still not ideal since it would
be pulling dusts up
>past our faces/respirators.
I would not rely on a Vent-a-Kiln for that. I've
never been convinced that they were sufficent
even for the kiln fumes they're designed for. I've
never measured the amount of air they actually move,
but I wouldn't trust one for dust removal.
You are quite correct, though, about the importance
of the direction of airflow. Anything that pulls the
bad stuff up past your face to remove it already has
a strike against it.
My solution, in a tight space with only 'through'
ventilation between doors and windows, is to work
with them shut to keep the breeze to a minimum
and let the dust settle to where it can be sponged
off of the work surface. I try to mix glazes just
before quitting for the day, or before a day off,
to give it time to settle. Not a great system, but
I think it's a better plan than lots of moving air
that stirs but doesn't directly remove the dust.
If you can afford to buy equipment, though, do it.
Here's one solution, which I just made up and
haven't tried: a welding work-station exhaust fan.
They are chute-shaped funnels a foot across which
rest on your work surface (some have magnets to hold
them in place) and can be moved about. They attach
to flexible tubing about 6" in diameter, which leads
to the actual fan mounted on an outside wall. Since
they sit near the work surface, they don't pull
the dust past your face, but keep it low instead,
and pull it directly out. The strength of the 'pull'
will depend on the fan you use.
I don't know if this is the best option, nor do I
know the cost for a single unit, but a call to a
welding supplier will provide that info. Welding
shops are serious about exhaust systems - they've
got OSHA looking over their shoulders.
-Snail
John Baymore on wed 6 jul 05
Marc and Christine,
You are on the right track with the vent idea. The reason that you can't
find "off the shelf" stuff is that this issue is actually far more
complicated than it first appears due to the fact that the installation
iteself is not as "uniform" as the venting of a small electric kiln.
There are a LOT of variables that affect ventilation system performance...
stuff like the exact location of the make up air source, the length of the
vent ducts both pre and post fans and their construction and pitch and
number of turns, the prevailing winds at the termination point, the dust
volume of the generating sources, and so on. This gets really important
because some of the materials typically being handled are pretty toxic.
Silica alone has a very low PEL and is specifically controlled under stuff
like OSHA laws. That kind of stuff makes manufacturers "nervous" . So
you won't find a "one size fits all" solution to this one, unfortunately.
What you are looking for are called slot hoods. They move a LOT of air
(creates a "wind" ) and create a stream of air that makes sure that
fresh air is brought thru your breathing zone before the flow picks up the
dusts at the scales / scooping area...and then brings them to the slot
hood and gets them out of the building.
For glaze weighing and mixing what you want is one or more of them located
on the counter top behind the weighing area. For mixing in buckets... the
location of the slot hood and makeup air should be such that it
accomplishes the same thing. Ditto any other process generating dusts.
Likely this dust control will take a few local pickup slot hoods. As you
plan things out, make sure that you don't lay it out to get your head
between the flow of fresh air AFTER the dust source and before the slot
hood.
I've been involved in a lot of ventialtion projects as a pro kiln designer
and ceramics consultant. When it comes to the technical details of the
stuff.... I bring in a ventialtion engineer. Unlike kiln installations...
a lot of HVAC firms have experience with industrial dust control
projects. (Not so with high fire fuel burning kilns.) So you should be
able to find someone in your area easily. It will be a "minor" project
for such a person... so it probably will not be too expernsicve to have
them spec out the job.
If you just HAVE to proceed with a "do it yourself" project....... err on
the side of moving WAY too much air rather than too little. For planning
I would recommend a book called "Industrial Ventilation: A Manual of
Recommended Practice" by the American Conference of Governmental
Industrial Hygienists. I got my first copy back in the early 70's and
newer copies have been in my professional library ever since.
The electric kiln vent type systems would not be anywhere near adequate
for this task.
Hope this helps a bit.
best,
..............john
JBaymore@compuserve.com
http://www.JohnBaymore.com
John Baymore
River Bend Pottery
22 Riverbend Way
Wilton, NH 03086 USA
"Please use compuserve address above for direct communications."
Marcus Lisle on thu 7 jul 05
Thanks very much to both of you, Snail and John,
for your in-depth analysis and good suggestions,
in your very thorough replies.
I can appreciate the need to have a solution designed
to our expected uses and unique studio characteristics,
and will see if we can afford a qualified consultant.
In the meantime, if there are any potters out there who
have built a local exhaust ventilation system for exhausting
dusts from glaze materials or plaster, or
if you know a good source for slot hoods and related components,
please chime in.
Thank you,
Marc
William & Susan Schran User on fri 8 jul 05
On 7/7/05 12:23 PM, "Marcus Lisle" wrote:
> In the meantime, if there are any potters out there who
> have built a local exhaust ventilation system for exhausting
> dusts from glaze materials or plaster, or
> if you know a good source for slot hoods and related components,
> please chime in.
I've not built/installed an exhaust vent system, but was wondering if a
kitchen vent hood/fan, with sufficient CFM air stream and a piece of plywood
attached across the open space leaving just a slot open (the slot
ventilation) would work for this application.
The user would be in front of the exhaust vent, with make up air behind.
Hmmm......
--
William "Bill" Schran
Fredericksburg, Virginia
Marcus Lisle on tue 12 jul 05
Thanks for your idea of utilizing a kitchen vent hood, Bill. We were thinking the same thing
recently too, but will probably have to turn to an HVAC consultant in order to make sure we
can piece together the most compatible components for venting dusts.
Thanks to all who have provided suggestions. When we finally arrive at an installed solution,
we will document it and share it with this list.
Marc Lisle &
Christine Cavalier
On Fri, 8 Jul 2005 07:43:40 -0400, William & Susan Schran User wrote:
>I've not built/installed an exhaust vent system, but was wondering if a
>kitchen vent hood/fan, with sufficient CFM air stream and a piece of plywood
>attached across the open space leaving just a slot open (the slot
>ventilation) would work for this application.
>The user would be in front of the exhaust vent, with make up air behind.
>Hmmm......
>--
>William "Bill" Schran
>Fredericksburg, Virginia
>On 7/7/05 12:23 PM, "Marcus Lisle" wrote:
>
>> In the meantime, if there are any potters out there who
>> have built a local exhaust ventilation system for exhausting
>> dusts from glaze materials or plaster, or
>> if you know a good source for slot hoods and related components,
>> please chime in.
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