Peltierilmiö

Peltierilmiö, also known as the Peltier effect, is a thermoelectric phenomenon. It describes the heating or cooling that occurs at the junction of two different conductors when an electric current passes through them. Discovered by Jean Charles Athanase Peltier in 1834, the effect is the inverse of the Seebeck effect, where a temperature difference between two dissimilar conductors creates an electric voltage.

When direct current flows through the junction of two different materials, heat is either absorbed or released at that junction. The direction of heat flow depends on the direction of the current and the types of materials used. One junction will get colder, while the other will get hotter. This heat transfer is a direct consequence of the differing energy levels of electrons in the two materials. As electrons move from a lower energy level to a higher one, they absorb energy (cooling effect), and as they move from a higher energy level to a lower one, they release energy (heating effect).

The magnitude of the Peltier effect is quantified by the Peltier coefficient, which is dependent on the specific pair of materials and the temperature. This effect is the fundamental principle behind thermoelectric coolers (TECs), also known as Peltier modules. These solid-state devices are widely used in applications requiring localized cooling or heating, such as in portable refrigerators, electronic component cooling, and temperature control systems where mechanical refrigeration is not feasible. While efficient for small-scale applications, Peltier devices are generally less energy-efficient than conventional refrigeration methods for larger cooling loads.