Peltier elements are thermoelectric components that can function both as heat pumps and as power generators.
As early as 1822, Thomas Seebeck observed that a closed circuit made of two dissimilar metallic conductors would generate a magnetic field when a temperature difference existed between the two junctions. The magnetic field was a result of an electric current flowing through the circuit — caused by a temperature-dependent voltage that developed between the contact points.
This principle is still applied today in temperature measurement using thermocouples. French physicist Jean Charles Athanase Peltier later discovered the reverse effect: when an electric current flows through such a circuit, a temperature difference develops between the junctions. At the time, the resulting temperature change was minimal and not suitable for practical use.
The Peltier effect gained commercial significance with the advancement of semiconductor technology. It became possible to produce materials with high thermoelectric voltage, low electrical resistance, and low thermal conductivity. Alloys of bismuth, tellurium, antimony, selenium, and various doping agents have proven to be effective in this field.
Today, Peltier technology competes with traditional compressor- and absorption-based cooling systems. While a direct comparison of costs per watt of cooling capacity often shows Peltier elements to be more expensive, their advantages are significant and application-dependent.
For low-capacity cooling applications, Peltier elements are extremely compact. They also offer precise temperature control via regulation of the operating current. Additionally, simply reversing the direction of current allows the same element to switch from cooling to heating.
If you would like to learn more about Peltier elements — including calculation principles, formulas, and practical application tips — please request our article “Guide to the Use of Peltier Elements.”