Charcoal kiln in California Indian brick kiln Hops kiln Farnham Pottery, Wrecclesham, Surrey with the preserved bottle kiln on the right of photo A modern tunnel kiln Fired ware on a kiln car exiting an intermittent kiln A kiln is a thermally insulated chamber, a type of oven, that produces temperatures sufficient to complete some process, such as hardening, drying, or chemical changes. Kilns have