Check with a professional electrician to determine what power your environment has and where your kiln should be placed. If the kiln will be used in a school, check with your maintenance personnel. Considerations include: Voltage — Voltage services can be 120V, 208V, or 240V. Most residences only have 120V and 240V, whereas commercial and institutional buildings may have all three available. Some 240V kiln models will have a higher temperature rating. Phase — All 208V and 240V service will be either single-phase or three-phase. Nearly all residential service is single-phase, whereas commercial and institutional services may have both available. Single-phase has two current-carrying wires and a ground, and three-phase has three current-carrying wires and a ground. These are both equally efficient; however, three-phase supplies allow for smaller wire and some kiln models designed for three-phase will have higher temperature ratings. Amps — The kiln size you’re considering could determine the amperage supplied to the building. Additional amperage may be added to your location by expanding the existing service.
This depends on the type of clay and glazes that will be fired in the kiln. Whether you use high fire or low fire clays will help you determine the maximum temperature for your needs. Clay High Fire Cone 5 (2167°F) and higher Low Fire Cone 05–06 (1828°F–1888°F
Glazes High Fire Cone 5 (2167°F) and higher Low Fire Cone 04–05 (1888°F–1945°F)
Testing has shown that carbon monoxide produced during firings can be higher than accepted government (OSHA) standards — 35 PPM (Parts Per Million) for continual exposure or 200 PPM for short-term exposure, which can cause headaches, fatigue, sore throats, and nausea. Fumes, odors, and vapors that contain organics, volatile metals, fluorides, and sulphur oxides are also created when clay bodies and glazes are fired. It is important to clear them out of inhabited spaces to ensure everyone’s safety and comfort. Kiln venting accomplishes that.
A downdraft vent removes fumes and odors from the kiln while also bringing in air, which improves heat distribution and circulation. This reduces the possibility of transferring color from one glaze to another inside the kiln, and also reduces corrosion of the kiln’s metal heating elements and kiln sitter parts. A venting hood does not vent the kiln but rather removes fumes that have already escaped. There are no firing benefits and only about 85% of the fumes are removed.
The quantity of pieces you want to fire at one time and the size of the artwork being produced will help you determine the size of the chamber you need. Also keep in mind the volume of work you’ll be firing during your busiest months.
An automatic kiln controller allows users to create precise, repeatable schedules. This provides consistent results — plus more creative control when experimenting. Delay and auto shut-off features also increase convenience and safety.