how do gas, oil, electric furnaces work/operate?

Question

i mean like actual process. thank you. step by step. Thank you!

Answer 1

Furnaces use heat to heat the air. A blower will send the heated air through ducts.

A thermostat switches the furnace on. Gas/Oil furnaces open the fuel valve to ignite the fuel. As cold air passes over the burners, it is heated.

For Electric furnaces, heat strips are used in lieu of fuel.