Furnace vs. Kiln — What's the Difference?

A furnace, referred to as a heater or boiler in British English, is a heating unit used to heat up an entire building. Furnaces are mostly used as a major component of a central heating system.

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 been used for millennia to turn objects made from clay into pottery, tiles and bricks.

An enclosure in which energy in a nonthermal form is converted to heat, especially such an enclosure in which heat is generated by the combustion of a suitable fuel.

Any of various ovens for hardening, burning, or drying substances such as grain, meal, or clay, especially a brick-lined oven used to bake or fire ceramics.

An intensely hot place

To process in one of these ovens.

A severe test or trial

An oven or furnace or a heated chamber, for the purpose of hardening, burning, calcining or drying anything; for example, firing ceramics, curing or preserving tobacco, or drying grain.

(UK) An industrial heating device, e.g. for smelting metal or baking ceramics.

To bake in a kiln; to fire.

A device that provides heat for a building; a space heater.

A large stove or oven; a furnace of brick or stone, or a heated chamber, for the purpose of hardening, burning, or drying anything; as, a kiln for baking or hardening earthen vessels; a kiln for drying grain, meal, lumber, etc.; a kiln for calcining limestone.

(colloquial) Any area that is excessively hot.

A furnace for burning bricks; a brickkiln.

(figurative) A place or time of punishment, affliction, or great trial; severe experience or discipline.

A large oven for firing or burning or drying such things as porcelain or bricks

To heat in a furnace.

To exhale like a furnace.

An inclosed place in which heat is produced by the combustion of fuel, as for reducing ores or melting metals, for warming a house, for baking pottery, etc.; as, an iron furnace; a hot-air furnace; a glass furnace; a boiler furnace, etc.

A place or time of punishment, affiction, or great trial; severe experience or discipline.

To throw out, or exhale, as from a furnace; also, to put into a furnace.

An enclosed chamber in which heat is produced to heat buildings, destroy refuse, smelt or refine ores, etc.