Heating System

Have you ever wondered how your home stays warm when it is freezing outside? It uses a heating system that transfers thermal energy into the air inside.

One common system is a furnace. While some furnaces use electricity, most burn natural gas to heat the air.

In an electric furnace, electricity heats metal resistance coils. Inside a gas furnace, burning fuel heats a metal heat exchanger. No matter the type, the metal component becomes extremely hot. When cool air blows across this hot metal, heat moves into the air by conduction.

This warm air then travels through ducts and vents to your room, and convection helps it spread out and raise the room temperature.

Some heating systems use hot water instead; a boiler heats water, and pumps move it through pipes to radiators.

In a radiator, the hot water transfers its heat to the metal walls by conduction.

Then, the hot metal warms the surrounding air through convection and radiates steady warmth into the room.