Heated air moves up one chimney while cool air moves down another.

Convection is a method of heat transfer in liquid and gases.
Learn about convection in real-world situations such as air-conditioning, building fires, and why the wind changes directions at the beach!

Air heated by a candle moves up one chimney while cooler air moves down another to replace the lost air. These currents can be seen against a dark backdrop. Includes: metal box with glass front; two glass chimneys. You need a smoke source.