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heat exhaust systems for kiln rooms - question

updated sat 8 apr 06

 

Kathi LeSueur on tue 4 apr 06


Janine LaMaie wrote:

>Dear Claypeople:
>
>This thread has me asking myself that if being in the dark on this subject
>is going to put me in the hot seat. Can someone explain the dangers in the
>kiln room when the air temp (and thus other objects?) is greater than 110F?
>or some other temp?
>
>In constructing the new studio, I have worked closely with building
>inspectors, hood fabricator/chimney supplier, and kiln builder. Both gas
>and electric kiln will be indoors in the kiln room and I would like to know
>what potential circumstances might be dangerous in firing either (or both!)
>in an enclosed space. Should I always leave the door open? The windows?>>>>
>

I've had my gas kiln and two electric kilns in the same room for about
sixteen years. I haven't noticed any problems with my electric kilns. I
have a hood over the gas kiln plus two turbines in the roof. You do
want to have a door or window open when firing to bring in fresh air.
But one of the mistakes people make is introducing too much air. I have
two overhead garage doors on that part of the studio. I open them each
about a foot. This was the advice of the man who made my hood. More than
that and there will not be a sufficient draft. I also would advise you
to line the room with fire resistant drywall.

Kathi

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Janine LaMaie on tue 4 apr 06


Dear Claypeople:

This thread has me asking myself that if being in the dark on this subject
is going to put me in the hot seat. Can someone explain the dangers in the
kiln room when the air temp (and thus other objects?) is greater than 110F?
or some other temp?

In constructing the new studio, I have worked closely with building
inspectors, hood fabricator/chimney supplier, and kiln builder. Both gas
and electric kiln will be indoors in the kiln room and I would like to know
what potential circumstances might be dangerous in firing either (or both!)
in an enclosed space. Should I always leave the door open? The windows?

Your thoughts and advice on or off list will be much appreciated.

Best regards,
Janine LaMaie
Tacoma, WA

p.s. It was absolutely a BLAST to meet many of you in Portland! The
combined energy, talent, and hospitality of this group is incredible!

Liz Willoughby on wed 5 apr 06


Dear Janine,
It is never stupid to post a question for information, and always
incredibly stupid to not post one for
fear of ridicule.
I think that we need to know how large your kiln room is. If you
have been working with building inspectors, that is a good start.
You will obviously need good ventilation. The danger of course is
carbon monoxide poisoning so you will need carbon monoxide detectors
in the kiln room, and also in any adjoining rooms. Even a bisque
firing in an electric kiln will give off carbon monoxide fumes. My
C.M. detector always registers a small amount of C.M. in the next
room, when I am doing a bisque firing.

By all means, open your doors and windows to the outside if it is
possible. You might find that if your windows or doors have that
hard plastic (?) window pane on them that they will bend and become
warped.

There was a story on clayart by a woman who had her electric kiln on
in the next room to her studio, and she became so ill that she had to
go to hospital. (She did not have a hood attached, and I think she
had a window open in the kiln room)

It isn't the heat so much that is a problem, as the gases emitted
from the kilns. But I would always open windows or doors if that is
possible.

Liz from Grafton, Ontario, Canada.

>
>This thread has me asking myself that if being in the dark on this subject
>is going to put me in the hot seat. Can someone explain the dangers in the
>kiln room when the air temp (and thus other objects?) is greater than 110F?
>or some other temp?
>
>In constructing the new studio, I have worked closely with building
>inspectors, hood fabricator/chimney supplier, and kiln builder. Both gas
>and electric kiln will be indoors in the kiln room and I would like to know
>what potential circumstances might be dangerous in firing either (or both!)
>in an enclosed space. Should I always leave the door open? The windows?
>
>Your thoughts and advice on or off list will be much appreciated.
>
>Best regards,
>Janine LaMaie
>Tacoma, WA

Arnold Howard on wed 5 apr 06


From: "Janine LaMaie"
Can someone explain the dangers in the
> kiln room when the air temp (and thus other
> objects?) is greater than 110F?

Switches, relays, and controllers on an electric kiln
fail when the room temperature gets too high. For
example, a customer kept sending us burned-out
infinite control switches. They eventually sent us
one of the switch knobs, which had gotten so hot that
the plastic distorted. We called to ask where they
were firing the kiln.

The customer had fired it in a small room at night
during the summer. They locked the door and windows
and left the kiln on while they were away.

Blowing a fan across the ventilation louvers is the
easiest way to lower the kiln's switch box
temperature. The fan should be positioned so that air
does not blow into a peephole. The air should be
directed toward the side of the switch box so that it
goes in one side of the box and out the other.

By the way, if switches keep burning out, it may be
due to a bad push-on connector. When a push-on
connector gets too hot, it loses its spring tension.
Even if you tighten the connector by squeezing with
pliers, it will loosen again. A loose connection
causes electrical arcing, which overheats the switch.

Sincerely,

Arnold Howard
Paragon Industries, L.P., Mesquite, Texas USA
ahoward@paragonweb.com / www.paragonweb.com

Maurice Weitman on wed 5 apr 06


At 12:49 -0500 on 4/5/06, Arnold Howard wrote:
>Blowing a fan across the ventilation louvers is the
>easiest way to lower the kiln's switch box
>temperature.

Hello, Arnold,

Why do you suppose kiln manufacturers rely on=20
convection to cool the kiln's electronics when a=20
$5 muffin fan would nearly completely eliminate=20
the problem you mention?

It seems obvious that when the kiln's skin is=20
routinely over 250=BA F., the safety and integrity=20
of electronics nearby would be compromised.

Regards,
Maurice

Ivor and Olive Lewis on thu 6 apr 06


Dear Janine LaMaie=20

You ask ...air temp (and thus other objects?) is greater than 110F?>....

Accepting what has already been said, I think if you intend remaining =
there for an extended period that Dehydration may be a problem. Keep =
plenty of cool fresh wholesome water handy and sip before you start to =
feel thirsty.

Best regards,

Ivor Lewis.
Redhill,
South Australia.

Darrell Walker on thu 6 apr 06


It seems like another alternative would be to provide an option for a
"remote" controller, like when you add a controller on to an existing
kiln.

-Darrell

On Apr 6, 2006, at 11:20 AM, Arnold Howard wrote:

> A fan in the switch box is a good idea especially for hot climates.
> A disadvantage is that a fan running all the time would eventually
> pull dust inside the switch box, causing components to overheat.
> But if enough people wanted it, manufacturers would certainly offer
> it.
>
> Using an external fan has been so effective that most people seem
> to be satisfied with it.
>
> Sincerely,
>
> Arnold Howard
> Paragon Industries, L.P., Mesquite, Texas USA
> ahoward@paragonweb.com / www.paragonweb.com

Arnold Howard on thu 6 apr 06


A fan in the switch box is a good idea especially for=20
hot climates. A disadvantage is that a fan running=20
all the time would eventually pull dust inside the=20
switch box, causing components to overheat. But if=20
enough people wanted it, manufacturers would=20
certainly offer it.

Using an external fan has been so effective that most=20
people seem to be satisfied with it.

Sincerely,

Arnold Howard
Paragon Industries, L.P., Mesquite, Texas USA
ahoward@paragonweb.com / www.paragonweb.com

----- Original Message -----=20
From: "Maurice Weitman"
Why do you suppose kiln manufacturers rely on
convection to cool the kiln's electronics when a
$5 muffin fan would nearly completely eliminate
the problem you mention?
It seems obvious that when the kiln's skin is
routinely over 250=BA F., the safety and integrity
of electronics nearby would be compromised.