Heat moves by conduction, convection, and radiation.
Conduction is the process that occurs in substances denser than air like water, wood and stone where the heat moves through the substance. Conduction occurs rapidly in metals like gold and copper and very slowly in insulation like fiberglass.
Convection is the process where air makes contact with substances that are conducting heat and the air is heated. Hot air rises and this movement makes room for cooler air and the process continues until the air and the surfaces are close to the same temperature.
Radiation is the process of infra-red energy emanating from a heated substance through space. The energy travels in a straight line at the speed of light until it is absorbed or reflected by another substance. It is important to remember that in order for heat to move by radiation, there must be space between the objects. The space can be as small as a few air molecules and still be effective. If the objects are touching, then the heat moves by conduction, not be radiation.

Last updated on October 15, 2010 by Heat Barrier XP Main