A furnace is a device used for heating. The name derives from Latin fornax, oven. The earliest furnace was excavated at Balakot, a site of the Indus Valley Civilization, dating back to its mature phase (c. 2500-1900 BC). The furnace was most likely used for the manufacturing of ceramic objects

The furnace components can be divided into three categories.
1- The burners, heat exchanger, draft inducer, and venting.
2- The controls and safety devices.
3- The blower and air movement.