Heat Transfer by Radiation
Heat transfer by radiation, abbreviated as \(Q_r\) or \(\phi\) (Greek symbol phi), also called heat radiation or radiation heat transfer, is one of four types of heat transfer: conduction, convection, mixing and radiation. Radiation is the flow of energy through electromagnetic waves such as infrared, light, microwaves, etc.
Heat Transfer by Radiation formula
| \(\large{ Q_r = \sigma \; A \left( T^4 - T_e^4 \right) }\) |
Where:
\(\large{ Q_r }\) = heat radiation
\(\large{ A }\) = area of radiating
\(\large{ \sigma }\) (Greek symbol sigma) = Stefan-Boltzmann constant
\(\large{ T }\) = temperature of object emitting
\(\large{ T_e }\) = temperature of environment