General information on heat radiation

Heat radiation:

Energy is dissipated and absorbed at each surface as electromagnetic radiation. Any type of radiation takes energy with it. The exchange increases or reduces the heat quantity of a body.

Heat radiation is electromagnetic radiation. This radiation is always present. It is somewhat difficult to deal with because it is not visible. However, its influence is undisputed when we consider the effect of the sun in the transition from day to night or the heat emanating from a campfire.

Every body emits heat radiation and receives heat radiation. The term "heat radiation" suggests that in this case temperature has a deeper significance.

From experience we know that we perceive hot objects such as the sun or a campfire even at a distance. These are effects of heat radiation. In the case of the sun more heat can be absorbed than we normally emit. The absorption of heat radiation is reduced in the shade (see image).

The opposite effect is present when we stay in a building with cold walls or under a cloudless, open sky at night. Our body emits more heat than it absorbs. We cool down and begin to freeze.

Clothing (conduction) and ambient temperature (convection) also have a significant effect on the examples.

The effects of heat radiation are based on the difference between emitted and absorbed heat radiation.

Emitting and absorbing radiation - the exchange of radiation - occurs at the surface of bodies.