Kira Campbell on mon 17 jan 00
-------------------
I am curious about a venting method for a kiln that is in the middle of a =
large
space, but with no direct access to the outside. Is it even possible to =
provide
an exhaust system in such a case?
Thanks,
Kira Campbell
Frederich, Tim on tue 18 jan 00
Kira,
Could you please provide more details on the size of the space and
distances that a vent would have to run. I can then try to answer your
question. Our vents can be vented over a long distance. If you want to
contact me directly, my number is 614-895-2663 ext.36.
Sincerely,
Tim Frederich, Orton Ceramic Foundation
> ----------
> From: Kira Campbell[SMTP:kira@squarefish.com]
> Sent: Monday, January 17, 2000 2:55 PM
> To: CLAYART@LSV.UKY.EDU
> Subject: Venting systems
>
> ----------------------------Original message----------------------------
> -------------------
> I am curious about a venting method for a kiln that is in the middle of a
> large
> space, but with no direct access to the outside. Is it even possible to
> provide
> an exhaust system in such a case?
>
> Thanks,
> Kira Campbell
>
GSM_ENT on thu 20 jan 00
Hi Kira!
Happy New Year!!!!
There are several types of venting systems in the market. Everything from an
updraft (metal "cone" with pipe positioned over the kiln-less desireable),
sidedraft (system positioned on a side of the kiln) and the downdraft
(positioned under the kiln. Downdraft is the most efficient as it draws down
the hot air in the kiln making it fire more evenly.
Orton has a very good downdraft system. The have an extensive laboratiry and
their Firing Foundation now called Firing Institute conducts constant firing
related research. I recommend to become a member of the Foundation -
Institute. The downdraft pulls out 100% of the gases to the exterior of the
bldg. You can have up to three (3) angles before needing to use a larger
size vent pipe.
Blue Diamond kilns offers a Freedom Vent. This system is attached directly
to the lid of your kiln. It has a charcoal filter that requires to be
changed annualy (depending on the frequency of the firing). It does not need
to be vented outside, the filter collects the gases/fumes. However, it is
not a 100% efficient; about 90%.
Regards,
MANUEL R A "TONY" DIAZ RODRIGUEZ
MAJ., US ARMY (RET.)
MASTER KILN REPAIR TECHNICIAN
----- Original Message -----
From: Kira Campbell
To:
Sent: Monday, January 17, 2000 11:55 AM
Subject: Venting systems
----------------------------Original message----------------------------
-------------------
I am curious about a venting method for a kiln that is in the middle of a
large
space, but with no direct access to the outside. Is it even possible to
provide
an exhaust system in such a case?
Thanks,
Kira Campbell
John Post on fri 21 jan 00
>The downdraft pulls out 100% of the gases to the exterior of the
>bldg. You can have up to three (3) angles before needing to use a larger
>size vent pipe.
I have a hard time believing that these downdraft vents can actually pull
out 100% of the gases. Maybe 95-99% but not 100%.
The reason I say this is that I have an Orton downdraft vent under my 6
cubic foot electric kiln. I used galvanized 4 inch pipe to vent to the
outside. The pipe makes only two turns. I riveted the pipes together and
have duct tape over each pipe joint. I still can smell the kiln if I am in
the room with it. Maybe I was a police dog in another life, but the bottom
line is that I can still smell the kiln. I called Orton and the kiln
manufacturer and they suggested adding another small hole to the bottom of
the kiln where the vent is. I did that and there was little change.
Now the kiln room isn't unbearable when the kiln is on (I have a 10 inch
exhaust fan mounted through the wall as well), but you can still smell the
kiln. Since heat rises I figure that some gases escape from the kiln
between the lid and the body as well as from around the small air gaps at
the peep holes. Maybe filling every little space with fiber would cut this
down. I just find it hard to believe that 3-4 small holes in the bottom of
a kiln is going to pull out 100% of the gases out. I don't think these 3-4
holes can create enough draw to keep some of the heat and gases from
escaping from the top. Maybe this 100% thing is a manufacturer's claim.
Maybe I need a vent that can give 110% performance. Since I'm not in the
room when the kiln is on, I'm content with the 95-99% performance of the
vent. It's just been my experience that this 100% claim hasn't held up.
John Post
Sterling Heights, Michigan
rp1mrvl@moa.net
Dave Finkelnburg on sun 23 jan 00
John,
You are doing an excellent job of thinking through this process--what
happens when you vent a kiln. The idea is to get the kiln under negative
air pressure. That means, if there are any holes in the kiln, air leaks
in, not out. As long as that happens, then very few if any fumes from the
firing should get into the room.
However, as has been pointed out on the list before, there are ways
fumes can escape. First culprit, the fan. Is it outside the room? If
not, on the discharge side of it--the positive pressure side--it can easily
leak. Sounds like your duct is already taped there, so that's probably not
the problem, but look for any possible leaks.
Second, if there are many holes in the kiln--like a gap around the lid,
etc--then the kiln may not be under negative pressure and fumes may go out
the openings.
During the part of the firing where you burn off organics, the volume of
gases given off inside the kiln can be significant. The kiln can go
positive in pressure due to the burning, producing a greater volume of gases
than the fan can pull off. This isn't likely, but it is possible.
Is the duct in good shape. I'm replacing mine right now because of
corrosion attacking the duct. I should have done it sooner. When I
smelled the last bisque fire, I discovered I had a problem.
Have you made certain your kiln really is under negative pressure when
you are firing? Easiest way is hold something producing smoke near an open
peep during firing. If the kiln doesn't pull the smoke in, but rather blows
it away, you don't have negative pressure in the kiln.
Hope this helps you find where your kiln leaks are.
Dave Finkelnburg in balmy southern Idaho where the partially thawed
pond reveals little goldfish swimming about!
-----Original Message-----
From: John Post
To: CLAYART@LSV.UKY.EDU
Date: Friday, January 21, 2000 11:22 AM
Subject: Re: Venting systems
----------------------------Original message----------------------------
>The downdraft pulls out 100% of the gases to the exterior of the
>bldg. You can have up to three (3) angles before needing to use a larger
>size vent pipe.
I have a hard time believing that these downdraft vents can actually pull
out 100% of the gases. Maybe 95-99% but not 100%.
The reason I say this is that I have an Orton downdraft vent under my 6
cubic foot electric kiln. I used galvanized 4 inch pipe to vent to the
outside. The pipe makes only two turns. I riveted the pipes together and
have duct tape over each pipe joint. I still can smell the kiln if I am in
the room with it. Maybe I was a police dog in another life, but the bottom
line is that I can still smell the kiln. I called Orton and the kiln
manufacturer and they suggested adding another small hole to the bottom of
the kiln where the vent is. I did that and there was little change.
Now the kiln room isn't unbearable when the kiln is on (I have a 10 inch
exhaust fan mounted through the wall as well), but you can still smell the
kiln. Since heat rises I figure that some gases escape from the kiln
between the lid and the body as well as from around the small air gaps at
the peep holes. Maybe filling every little space with fiber would cut this
down. I just find it hard to believe that 3-4 small holes in the bottom of
a kiln is going to pull out 100% of the gases out. I don't think these 3-4
holes can create enough draw to keep some of the heat and gases from
escaping from the top. Maybe this 100% thing is a manufacturer's claim.
Maybe I need a vent that can give 110% performance. Since I'm not in the
room when the kiln is on, I'm content with the 95-99% performance of the
vent. It's just been my experience that this 100% claim hasn't held up.
John Post
Sterling Heights, Michigan
rp1mrvl@moa.net
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