General notes on ventilation of kiln room for electric kilns
All electrical kilns will produce heat when firing. The outside temperature of a front loading kiln can be as high as 120 degrees which is too hot to touch but not hot enough to cause ignition. The actual amount of heat produced by a kiln varies considerably depending upon the maximum firing temperature, density of load and length of firing. As a general guide electric kiln during pottery firing will emit between 1.3 and 2.6kW/hour for each 100 litres of kiln capacity.
A small electric kiln in a large room with adequate ventilation i.e. an open window, should not cause any problems, but if the kiln is large and/or in a smaller room, then the room should have additional ventilation. We recommend a canopy is fitted to the kiln to collect the heat which should then be ducted to atmosphere through an adjacent wall or window to assist ventilation. For a school, a dedicated extraction system could be installed in the kiln room. Please not that any extracted air would need to be replaced via a window or door grill and if the kiln was fired overnight any ventillation system would need to be running for the whole of the firing period. To the best of our knowledge it is not necessary to fireproof the extract ducting from a kiln room for electric kilns.
The kiln itself will not produce any fumes. Most material used in hobby ceramics are safe and produce minimal fumes. Certain materials like lustres and ceramic transfers can produce more harmful fumes when fired in quantity, but are rarely used in school/hobby kilns. any information on these products must be obtained from the specific material manufacturer or supplier.
Within 2m of each kiln should be fitted a suitably rated fuse isolation switch ( approximately 1.5m from the floor) to which the kiln must be connected. The kiln controller is simply plugged into a socket at the rear of the kiln and mounted on an adjacent wall.
HSE [Health and Safety Executive] free leaflet is downloadable from the HSE website.