• Welcome to The Building Code Forum

    Your premier resource for building code knowledge.

    This forum remains free to the public thanks to the generous support of our Sawhorse Members and Corporate Sponsors. Their contributions help keep this community thriving and accessible.

    Want enhanced access to expert discussions and exclusive features? Learn more about the benefits here.

    Ready to upgrade? Log in and upgrade now.

Kiln Exhausting Into Public Way

Mule

REGISTERED
Joined
Oct 19, 2009
Messages
1,520
Location
Texas
We have an exisiting elementary school with a small kiln, less than 20 cubic feet, that has a hood that when closed, turns on a fan that pushes the exhaust horizontaly through an adjacent exterior wall and directly over a covered walkway where students and teachers walk. The school is doing a major renovation and work is being performed in this room so I want to get it right!

This was probably installed in the 80's without any permits or inspections.

Is the exhaust from a kiln considered hazardous and required to comply with Section 510 of the 2006 IMC? Or would it be under "General" sections?

They are wanting to turn it 90° the run horizontally down past the covered walkway and exhaust into the open area.

I told the contractor they need to secure a copy of the manufactuers installation procedures to figure out how far the fan will push the exhaust. I don't think it is an option to go straight up because of exisitng construction, hard ducts, electrical...blah blah blah because the school was built in the 60's and added onto numerous times.

What else?????
 
* * *

Mule,

If you are using Section 502.14 [ in the `06 IMC ] to get to

Section 510, have you also looked at Section 501.2.1, # 2 ?

501.2.1 Location of exhaust outlets.

The termination point of exhaust outlets and ducts discharging to

the outdoors shall be located with the following minimum distances:

1. For ducts conveying explosive or flammable vapors, fumes or dusts:

30 feet (9144 mm) from property lines; 10 feet (3048 mm) from

operable openings into buildings; 6 feet (1829 mm) from exterior walls

and roofs; 30 feet (9144 mm) from combustible walls and operable

openings into buildings which are in the direction of the exhaust

discharge; 10 feet (3048 mm) above adjoining grade.

2. For other product-conveying outlets: 10 feet (3048 mm) from the

property lines; 3 feet (914 mm) from exterior walls and roofs; 10 feet

(3048 mm) from operable openings into buildings; 10 feet (3048 mm)

above adjoining grade.

3. For environmental air duct exhaust: 3 feet (914 mm) from property

lines; 3 feet (914 mm) from operable openings into buildings for all

occupancies other than Group U, and 10 feet (3048 mm) from

mechanical air intakes.

4. For specific systems: For clothes dryer exhaust, see Section 504.4;

for kitchen hoods, see Section 506.3; for dust, stock and conveying

systems, see Section 511.2; and for subslab soil exhaust systems, see

Section 512.4.

Also, see Section 923.1 GENERAL [ in the `06 IFGC, 5th Printing ]:

SECTION 923 SMALL CERAMIC KILNS:

923.1 General. "The provisions of this section shall apply to kilns that

are used for ceramics, have a maximum interior volume of 20 cubic

feet (0.566 m3) and are used for hobby and noncommercial purposes."

Section 923.1.1 Installation. "Kilns shall be installed in accordance

with the manufacturer’s installation instructions and the provisions of

this code."

Because your kiln is a 'direct vent' type of appliance, also look at

Section 804.3.4 [ in the `06 IFGC, 5th Printing ]: - Horizontal

terminations.



Horizontal terminations shall comply with the following requirements:

1. Where located adjacent to walkways, the termination of mechanical

draft systems shall be not less than 7 feet (2134 mm) above the level

of the walkway.

2. Vents shall terminate at least 3 feet (914 mm) above any forced

air inlet located within 10 feet (3048 mm).

3. The vent system shall terminate at least 4 feet (1219 mm) below,

4 feet (1219 mm) horizontally from or 1 foot (305 mm) above any door,

window or gravity air inlet into the building.

4. The vent termination point shall not be located closer than 3 feet

(914 mm) to an interior corner formed by two walls perpendicular to each

other.

5. The vent termination shall not be mounted directly above or within

3 feet (914 mm) horizontally from an oil tank vent or gas meter.

6. The bottom of the vent termination shall be located at least 12

inches (305 mm) above finished grade.

* * *
 
Last edited by a moderator:
Thanks for the reply. I've looked/read those sections. I am wondering what kind of fumes I actually have coming from a kiln.

Is..

For ducts conveying explosive or flammable vapors, fumes or dusts...

Is kilns any of these???

As you can tell I know NOTHING about kilns except they get hot and bake stuff.....cornbread, pies, cakes stuff like that.

Does the stuff they bake.......what is that word called???????? You know you put that little trinket out of clay in there with paint and ?????????? what???? Fire it???? is that the word???

Any way does this "stuff" omit any type of gas off that requires something other than the "general" requirements as found in..Section 501.2.1, # 2?
 
* * *

Mule,

I'm not sure of exactly what is exhausted out of those "hobby type"

of appliances ( kilns ).

I will have to defer to someone on here who is much more knowledgeable,

such as Dr. J, Hearthman, Hazmatpoobah, FM William Burns,

Uncle Bob, vegas paul, Builder Bob, peach, or one of the many other

exceptionally well qualified individuals on here. Sorry!

Do you know the manufacturer of your kiln? I can try to assist that

way. :)

* * *

* * *
 
There is some out-gassing. Usually moisture from the clay and some from the paint. But, depending on materials, most 'paint' for ceramics is some form of silica or silica-like substance and melts to fuse with the base material.

My mom was a ceramist and had a kiln in the utility room off of the kitchen. Never had issues that I know of.
 
agree with pyrguy! How about turning thee 90 up and exhausting higher. Exhaust should be mostly moisture and some salts. 20 cubic feet is a small unit, but larger then in most homes.
 
Thanks for all of your replies. I have asked for the specs on the kiln. Maybe I'll get them.

By the way this is a type of post that Uncle Bob is talking about on his post "What's New". I was hoping that the post would show up when I opened the forum this AM but I had to go do a search under my name and "find posts on this forum" to pull up additional answers. The only way to get around this would be to subscribe to the post.

Again thanks for all your help.
 
Mule Small Kilns are as per manufactures instruction as reference in the IMC 2006. Exhaust discharge would need to meet all other requirements referenced in the code for public way etc. Have fun!
 
Back
Top