When it’s cold outside, we turn on the heat in our houses, and soon we’re warm and cozy. But just how does it work?

A stove or heater raises the temperature of the air around it. The hot air expands, so it is lighter than the colder air. The heated air rises, and cooler air replaces it.

The movement of heated air away from a hot object and the flow of cooler air toward that object is called a convection current. The movement of the air carries heat to all parts of a room.

Source: The World Book Encyclopedia

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