A Furnace is a device used for heating. It does this through burning propane, natural gas, other something else flammable. The word has different meanings, though:

• In American English, it is the name for a heating system in the house. British English usually calls such systems boiler, heater or kiln.
• There are industrial furnaces; these provide heat so some processes can take place. An example of such a furnace would be the use in metallurgic processing. Blast furnaces for example make iron.

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