John Hesselberth on sat 24 jan 04
Hi Everyone,
I got a note from Maurice Weitman pointing out that Bailey kiln vent
was not designed the way I thought it was. He is right. I don't know if
they have changed or I had not remembered correctly. Anyhow I want to
clarify. In my opinion, from the standpoint of good engineering the
design, the blower should be wall mounted so there is no duct (dryer
vent or whatever) on the pressure side of the blower.
The blower should blow directly through the wall of your studio to the
outside. Why? I have rarely seen a duct on one of these systems that is
sealed air tight. They either have leaks around the fittings or pin
holes in the duct itself due to the corrosive nature of the fumes. And
when they have leaks they blow some of the fumes right back into your
studio. Maybe not a lot, but why settle for poor design?
At this point, the only kiln vent I am aware of having this design
feature is the L&L. Perhaps the new Orton design does also--I await
Arnold's assessment. The only pictures I see on the Orton site are
either under the kiln or a floor or suspended mount off to the side of
the kiln with a piece of dryer vent leading out through the wall. This
gets the blower away from the extreme heat of the kiln, but does
nothing to address my concern.
If you do have one of the systems that uses duct on the pressure side
of the blower, make sure you seal it as tightly as you can and inspect
it for pinhole leaks before every firing.
If there are others designed the way I describe above I would certainly
like to know about them. I frankly find it disappoiinting that systems
with pressure-side duct work are being offered so frequently when this
problem is so obvious and so solvable.
Regards,
John
http://www.frogpondpottery.com
http://www.masteringglazes.com
Hendrix, Taylor J on mon 26 jan 04
Oh wise froggie one!
Something else to think about. Mounting the blower on the wall may not
be the most practical in some situations. I am still thinking about how
I will mount the vent I have. As it stands, I have no good place to put
the blower against the outside wall unless I am willing to place it in
the roof space or drill through my brick veneer. Neither makes me very
comfortable. If I opted for the attic thing rather than poking a hole
in my garage wall, I would need a circuit for the blower, and I would
need to hard wire it. No way am I going to snake extension cords in my
attic. A new circuit is out. I have no more room in my poor overworked
box. The kiln took care of that. So, I am left with the blower
somewhere else. Arnold's suggestion to duct the blower with pvc pipe
where possible sounds very good. While dryer ducting may fail to the
corrosive nature of kiln gasses, I can't imagine pvc pipe doing so.
Metallic ducting at the kiln and a little beyond followed by the blower
and then pvc pipe to the outside is a reasonable compromise. I don't
think it would be too difficult to insure gas tight fits where
necessary. Inspecting the equipment on a regular basis wouldn't hurt
either.
Taylor, in Waco
-----Original Message-----
From: Clayart [mailto:CLAYART@LSV.CERAMICS.ORG] On Behalf Of John
Hesselberth
Sent: Saturday, January 24, 2004 6:17 PM
To: CLAYART@LSV.CERAMICS.ORG
Subject: Kiln Vents--Another Look
Hi Everyone,
I got a note from Maurice Weitman pointing out that Bailey kiln vent
was not designed the way I thought it was. He is right. I don't know if
they have changed or I had not remembered correctly. Anyhow I want to
clarify. In my opinion, from the standpoint of good engineering the
design, the blower should be wall mounted so there is no duct (dryer
vent or whatever) on the pressure side of the blower.
...
william schran on mon 26 jan 04
John wrote: >I got a note from Maurice Weitman pointing out that
Bailey kiln vent
was not designed the way I thought it was. In my opinion, from the
standpoint of good engineering the
design, the blower should be wall mounted so there is no duct (dryer
vent or whatever) on the pressure side of the blower. At this point,
the only kiln vent I am aware of having this design feature is the
L&L<
John - I'm confused. The Bailey & L&L vent systems work almost
exactly the same. When I was looking to replace my "over the kiln"
collection vent (that never worked very well), I looked carefully at
both the Bailey & L&L. Both have blower/motor mounted away from the
kiln. Both have a vent duct attached to the kiln, running to the
blower/motor. The L&L has a small flap that goes over the blower
intake to regulate the amount of air being drawn from the kiln. The
Bailey has the duct mounted on the wall of the kiln leaving a small
gap at the point of attachment to allow for the introduction of
secondary air maintaining negative pressure. Is this the difference
that you write about?
In my circumstance, I have the blower/motor mounted on a board that I
insert in an open window, seal the edges and close the window down on
the board. All seams along the duct are sealed with metal duct tape.
Are you writing about the duct running from the kiln to blower, then
another duct running from blower to outside? Then I agree with you.
Bill
John Hesselberth on tue 27 jan 04
On Monday, January 26, 2004, at 06:02 PM, william schran wrote:
> John - I'm confused. The Bailey & L&L vent systems work almost
> exactly the same. When I was looking to replace my "over the kiln"
> collection vent (that never worked very well), I looked carefully at
> both the Bailey & L&L. Both have blower/motor mounted away from the
> kiln. Both have a vent duct attached to the kiln, running to the
> blower/motor. The L&L has a small flap that goes over the blower
> intake to regulate the amount of air being drawn from the kiln. The
> Bailey has the duct mounted on the wall of the kiln leaving a small
> gap at the point of attachment to allow for the introduction of
> secondary air maintaining negative pressure. Is this the difference
> that you write about?
Hi Bill,
I thought they were too and maybe they used to be. Look at the Bailey
kiln vents on their web site now. I don't see the wall mount feature.
They appear to be designed to sit on the floor to the side of the kiln
with another piece of ductwork leading to the wall. It is that piece of
ductwork on the pressure (outlet) side of the fan I object to. It
provides a good opportunity for fumes to get back into your studio.
The ductwork in the studio, in my opinion, should all be under slightly
negative pressure (on the inlet side of the fan) so any leaks result in
studio air being drawn into the duct instead of kiln fumes being blown
into the studio. Wall mounting the blower solves that problem about as
well as it can be solved. You have to be sure the blower is well sealed
at the wall, but that is a whole lot easier thing to do than to worry
about several feet of ductwork that is usually hard to get to and
inspect regularly.
Regards,
John
http://www.frogpondpottery.com
http://www.masteringglazes.com
John Hesselberth on tue 27 jan 04
Hi Taylor,
Yes I would agree that PVC would be far better than dryer ducting on
the pressure side of the blower providing the PVC joints really are
sealed and not just slip-fit. In your situation that may be the best
you can do. Maurice's suggestion of a CO monitor is also a good one.
Regards,
John
On Monday, January 26, 2004, at 06:49 PM, Hendrix, Taylor J wrote:
> Arnold's suggestion to duct the blower with pvc pipe
> where possible sounds very good. While dryer ducting may fail to the
> corrosive nature of kiln gasses, I can't imagine pvc pipe doing so.
http://www.frogpondpottery.com
http://www.masteringglazes.com
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