Conduction, Convection, and Radiation

Introduction to Heat Transfer00:00:10

Heat transfer refers to how heat energy moves from one point to another, whether on Earth, in the atmosphere, or in space. There are three main types of heat transfer: conduction, convection, and radiation.

Conduction00:00:39

Conduction is the transfer of heat through molecular contact. An example is a metal spoon heating up when held over a flame; the energy from the flame causes molecules to vibrate and transfer energy throughout the spoon. Conduction is most effective in solid materials.

Convection00:01:36

Convection is heat transfer due to density differences. When air near a flame heats up, it expands, becomes less dense, and rises, carrying heat energy upwards. This process is most effective in liquids and gases.

Radiation00:02:26

Radiation is heat transfer by wave motion, specifically electromagnetic waves. Heat from a flame not only rises (convection) but also travels outwards in waves. Radiation does not require a material medium to travel, which is how energy from the sun reaches Earth.

Summary and Example with a Campfire00:03:01

The three types of heat transfer are conduction (contact), convection (density differences), and radiation (waves). A campfire provides a good illustration of all three: conduction heats a pot placed over the flame, convection causes heat to rise, and radiation emits heat outwards in waves.