Heat Transfer

Heat Transfer

Heat travels from a hot object to a cold object.
You might say that heat flows down a temperature hill.
So how does heat travel from one object to another?
By Conduction, Convection and Radiation.

Liquids and gases do not conduct heat very well, but they can transfer heat by CONVECTION.
Convection, heat is transferred from one place to another by the motion of the gas or liquid.



CONDUCTION is the main way for heat to transfer through solid materials. For example, the outside surface of an engine gets hot because heat energy is transferred from the combustion chamber through the metal to the outside surface.

All solid materials conduct heat, but some do a better job than others. Generally, metals are good conductors while porous materials are not.

Styrofoam is an example of a poor conductor.
It is a great insulator.
Good conductors of electricity are usually good conductors of heat.


The easiest way to explain heat transfer by RADIATION is by the heat we feel from the sun.
Even though the sun is about 93 million miles away from the earth, we still feel some of its heat.
It travels to earth through the vacuum (no air) of space by way of rays!