The most popular type of kiln for school use is the top-loading kiln. Top-loading kilns provide the best value in terms of cost per cubic foot. They are cost effective, easy to install and easy to maintain. Maintenance and repair costs are much lower when compared to other kiln styles. The design of top loading kilns allows for each kiln section to be disassembled for repair and for moving from one location to another. Parts for top loading kilns are readily available and are more economical than parts for other kiln styles.

When choosing between various sizes of kilns, there are many factors to consider:

1. How many students will be participating in your ceramics program?
2. How many pieces will each student be allowed to create during a given clay cycle? How large will those pieces be?
3. To what temperature range will you be firing the kiln?
4. How large is your kiln room?
5. How tall is the teacher who will be loading the kiln?

The number of students participating in your ceramic program at any given time is an important factor to consider with regard to kiln size. A group of 100 students participating in your ceramic program will require a larger kiln than a group of 50 students. The most popular size kiln for all ceramic programs is a 22-3/8" diameter by 27" high (6.7 cubic feet) kiln.

The number of pieces allotted to each student is another determining factor when comparing kiln sizes. Large groups of students participating in a ceramic program will need a larger kiln. If you are having trouble deciding between two kiln sizes, its always best to go with a slightly larger kiln. It’s better to have a little extra room left over in the kiln as opposed to not enough space to fire all of the student work. A larger kiln also allows the more freedom for the students to increase the size of their work.

This is a very important factor to consider when selecting your kiln. Typically, most elementary and middle schools fire the kiln in the Low-Fire Temperature range ∆06-∆04. Junior high and high schools fire anywhere between low fire ∆06-∆04 and mid-fire ∆5-∆6. Colleges and universities often fire to all temperatures, from low fire all the way up to high fire ∆10-∆12. Some larger kilns are not able to get up to mid-fire or high fire temperatures when operated on certain electric lines. These larger kilns require more amperage than their smaller counterparts. If you have an electric line already in place at your school, and the school is unable to upgrade that electric line- you will be limited with either kiln size or firing temperature. It is advisable to always double check the electric specs and requirements before purchasing a kiln for your school.

When selecting a desired temperature range for your program, it is extremely important to also select the correct clay body for that temperature. Low-fire glazes can be fired onto low-fire clay bodies. They can also be fired onto mid-fire and high fire clay bodies. Conversely, mid-fire glazes and high fired glazes should never be fired to maturity on low-fire clay bodies. Doing this could result in catastrophic consequences for your kiln. Damage to your kiln’s furniture kit and kiln chamber due to over-firing can be extremely costly and in some cases may render the kiln a complete loss. Always exercise extreme caution when selecting glaze and clay for your program.

Here are some helpful links explaining kiln temperature, the use of pyrometric witness cones, and the firing process in an electric kiln:

Orton Pyrometric Cone Chart explaining the way the ceramic industry measures temperature: Click here

View/Download PDF: Click here

The ceramic process and firing tips: Click here

A series of practical tips for firing a kiln from Orton: Click here

How to load your kiln properly: Click here

In the end, the size of your kiln room will dictate what size kiln is possible for your classroom. All kilns require at least 18” between the kiln and all surrounding surfaces & objects. You should maintain a minimum of 36” between kilns, especially if they will be firing at the same time. The floor material underneath the kiln should be concrete or tile. Kilns should never be installed on top of wood floors. Two layers of masonry board can be laid over top of wood and linoleum floors. The masonry should extend out at least 12” all around the exterior circumference of the kiln. Doing this will protect the floor from the heat of the kiln.

Here is a helpful link for installation in kiln rooms: Click here

The height of a the kiln operator may be a limiting factor when it comes to selecting a kiln. A fully assembled, 3-section tall kiln measures 38” high from the floor to the top ring of the kiln. When loading a top-loading kiln, you will need to bend over to reach the bottom of the kiln during the start of the loading process. If you are not tall enough to reach the bottom of the kiln easily, you may push the kiln out of alignment or damage the top kiln ring by leaning on the kiln to reach the kiln floor. Kiln operators who are about 5ft 4” and shorter may want to opt for the shorter 2-section tall kilns. This will enable them to reach the bottom of the kiln without placing stress on the top ring. You can make up for the loss of height by choosing a 2-section tall kiln with a larger diameter- this way you wont lose too much cubic footage with the height reduction. All L&L kiln models provide a height guide in their respective kiln specification sheets. These specification sheets can be found in the specifications tab under each product page.

Certain kiln models are more appropriate than others for the different stages of the K-12 school system. Below is a rough guide for common kiln models for the various stages.

ELEMENTARY & MIDDLE SCHOOLS

• School-Master SM23T-3 Package (Low-Fire, Cone 6, 6.7 cubic feet, 38 bowls)
• Easy-Fire e23T-3 Package (High-Fire, Cone 10, 22" Diameter by 27" High, 6.7 cubic feet, 38 bowls)
• Easy-Fire e28S-3 Package (High-Fire, Cone 10, 28" Diameter by 18" High, 6.8 cubic feet, 50 bowls)

Advanced Middle School & High School

• eQuad-Pro eQ2827-3 Package (High-Fire, Cone 10, 28" Diameter by 27" High, 10.2 cubic feet, 74 bowls)
• Easy-Fire e28M-3 Package (High-Fire, Cone 10, 28" Diameter by 22" High, 8.5 cubic feet, 62 bowls)
• Easy-Fire e28T-3 Package (High-Fire, Cone 5 to 10 depending on voltage, 28" Diameter by 27" High, 10.2 cubic feet, 74 bowls)

Advanced High School

• eFL Series eFL2635 Package (Front-Loading, High-Fire, Cone 10, 26” Wide x 35” High x 26” Deep, 13.7 cubic feet, 128 bowls)
• DaVinci Series T2327 Package (Top-Loading, High-Fire, Cone 10, 34.75” Wide x 27” High x 26.5” Deep, 14.4 cubic feet, 108bowls)