There are three basic mechanisms by which heat is dissipated from electronic components such as those found in a power supply: radiation, conduction and convection. Radiation through electromagnetic emission provides one means by which heat transfers between elements at different temperatures, so a transformer might radiate heat to the surrounding case of the supply. The calculation of radiant heat transfer is complex and affected by many factors such as the spacing between elements and the color and finish of surfaces, not just the temperature differential. Fortunately, this form of heat loss is rarely the primary means of dissipation. Conduction and convection cooling are more relevant thermal management techniques for power supplies.