Kiln Room Design
A guide to properly designing an area to locate a kiln for schools and other facilities.
This document is to be used as a general reference. Always make sure you consult Local and National Building and Electrical Codes. You can view the full PDF at https://skutt.com/images/Designing-A-Kiln-Room-1.pdf?srsltid=AfmBOopGCBDe__8WffoRWKlNmwD9v2-cKCJUUEU9KhL0il3WGaH7oV_a
INTRODUCTION
Kilns for firing ceramics and glass are installed safely in thousands of schools, universities, community centers and homes across the nation every year. The following guidelines were established to help architects and contractors design areas to locate the kiln which are safe, efficient, and user friendly.
DESIGNING THE ROOM
The size of the room will be dictated by several factors:
- The size of the kiln
- The number of kilns
- HVAC design
- Teacher requirements
Skutt kilns have been tested to be safe by Underwriters Laboratories when installed a minimum of 18” (46 cm) from any wall or combustible material.
When multiple kilns are installed, they may be placed as close as 18” (46 cm) apart, however it is important to orient the kilns so the controller does not face the other kiln or kilns. This is to help limit the heat exposure to the controller.
It is a good idea to have a kiln room that can be secured from children and pets entering the room. The art teacher will need a place to store ceramic ware, kiln shelves, and other items used in conjunction with the kiln. If possible, consult them with regards to their storage needs when planning the size of the room.
WALL AND FLOOR COVERINGS
No special wall material is required when the kilns are placed at the designated setbacks. Kilns must be placed on a non-combustible floor such as concrete or ceramic tile. It is not recommended to place the kilns on wood, carpet, or vinyl floors which may discolor or ignite from the heat of the kiln.
If a noncombustible floor is not available, one may be constructed. Uniform mechanical code requires the floor to be constructed of a minimum of 2” (5 cm) thick solid masonry extending a minimum of 12” (31 cm) beyond the outer perimeter of the kiln.
KILN ROOM PREPARATION
FIRE SYSTEM
Sprinkler heads or heat sensors should not be placed directly above the kiln. Sprinkler heads and heat sensors come in a range of temperature ratings. Any sprinkler head or heat sensor in the room must be adequately rated so that they will not be activated through normal use of the kiln. Whenever possible use the maximum rating allowed by local code.
ROOM COOLING
Skutt Automatic Kilns are designed to shutoff if the electronics get too hot. In order to prevent this from happening the room must be kept below 100oF (38oC). Depending on the room size, this will most likely require some HVAC design and installation. We publish the maximum BTU output for each model to assist you in making the proper calculations.
ACCESS, STORAGE AND FUNCTIONALITY
Consult with the Art Teacher whenever possible to determine how they plan on using the room. They will need easy access to the controller and to open and close the lid. The kilns do get hot, so you may want to design a way to limit access to the kiln when desired. In most cases it will be necessary to plan space for storage and racks. Often times the teacher will also want the room designed large enough to perform other related activities such as glazing and drying ceramic ware.
FUME VENTILATION
Clay, glazes and other items that are fired in the kiln can emit odorous fumes that need to be vented from the room. This is best done through the use of a Downdraft Vent, such as the EnviroVent 2. Unlike overhead vents, it captures the fumes before they are allowed to enter the room. These units draw a small amount of air from the kiln chamber and use room air to cool it before it is forced outside through duct work. Some local codes require that you use a negative pressure vent system like the EnviroVent 2.
All manufactures of kilns recommend active fume removal through the use of a Downdraft Vent. Downdraft Ventilation was invented by the Orton Foundation for the purpose of removing 100% of the fumes from the room. By actively removing the fumes from the kiln chamber, the quality of the ceramics, heat uniformity and component life is greatly improved. Overhead venting systems do not provide these added benefits and also require the operator to prop the lid at the beginning of the firing and then return to lower it when the kiln reaches 1000oF (538oC).
Downdraft vents may be vented through the wall or the roof. When vented through the roof, it may place the in-line switch for the fan motor out of reach. If this is the case, it will be necessary to wire the outlet for the vent to a switch which is easily accessible. Visit the web site for specific installation specifications.
Systems for venting fumes and heat should be operated independent of the schools main HVAC system. Shutting down the system during a firing could cause the room to overheat and activate the sprinklers. A vent shut off system is available through Skutt that works in conjunction with the kilns controller.
In addition to a downdraft vent, you may also need air conditioning or a larger room vent to prevent the room from exceeding 100oF (38oC ) or other maximum temperature designation. Use the BTU ratings of the kiln to calculate the venting or air conditioning needed.
Make-up air will need to be provided for the 140 CFM (3.96 CMM) that are vented outside by the Downdraft vent and HVAC systems. This is often done by installing a vent panel in the kiln room door or wall.
ELECTRICAL AND COMMUNICATIONS
THE RIGHT VOLTAGE OR PHASE
Unlike many appliances, kilns are designed to run on a specific voltage, either 240V or 208V. Therefore, it is extremely important to order the kiln that matches the supply. We can design units that run on either 1 phase or 3 phase power supplies. They cannot be easily or cheaply converted, so as with voltage, make sure you order a unit that matches your phase supply. Certain models have a lower temperature rating when hooked up to 208V/1 phase supply, so if you have a choice, you may want to consider using a different supply or a different kiln model.
WIRE TYPE AND SIZE
Kilns can be susceptible to drops in voltage caused by inadequately sized wiring or heavy draws on the power grid caused by other equipment. Be sure to use adequate sized wire and dedicated circuits to help avoid this problem. A list of suggested wire gauges can be found on the web site. We recommend using only copper wire. Always consult local and national electrical codes when determining adequate wire size for length and circuit method used.
OUTLETS AND PLUGS
Most kilns used in schools come equipped with a NEMA 6-50 plug if they are 1 phase or a NEMA 15-50 plug if they are 3 phase. The PK line of kilns is designed to go to higher temperatures and must be hard wired. The power cords exit from the control box in the front of the kiln and are 6 ft. (1.8 m) long. Locate the wall outlet (or junction box for direct wire kilns) to the right side of the kiln 18” (46 cm) to 40“ (102 cm) from the floor and close enough for the end of the power cord to reach the outlet without touching the kiln or putting strain on the plug. Direct wire kilns will need a means of disconnect visible from the kiln or lockable. Remember that you will want to also wire a 120 Volt outlet near the kiln to power a Downdraft Vent, and/or KilnLink Box (KM kilns only).
WIFI AND INTERNET CONNECTION
Both Skutt KM and KMT kilns have the ability to connect to the Internet for purposes of remote monitoring, diagnostics and data logging using KilnLink. KMT kilns have built in WiFi. They require a signal that does not have a captive portal to connect, only a user name and password. If a WiFi connection without a captive portal is not possible, you may need to purchase a standard KM kiln that connects to the internet with a standard Ethernet cable and additional hardware (KilnLink Box and factory installed Link Board).