Thermoelectric Cooler - Peltier Elements

Thermoelectric coolers have the ability to cool or warm objects in liquid or solid condition, by means of increase or decrease of temperature. In contrary to steam- or refrigerating-compressors the thermoelectric elements are miniature components based on semiconductor properties.

Peltier elements function based on an effect detected in the year 1834 by the French watch-maker named Peltier. I.e. during transition of electricity at the contact point of two different metals a temperatur difference against the ambient temperature is noticeable. This effect was only improved and utilized in the recent years.

A Peltier Element consists of two differently doped semiconductor legs which are connected at the face. During the flow of direct current through this element one side cools down and gathers thermal energy from its environment which will be dissipated into the environment from the other side. An increase of this temperature difference can be achieved by cascading several elements. The Peltier Element practically “pumps” thermal energy from the warm to the cold side. When reversing the current the flow of the thermal energy will be also reversed and the element can be used for heating purposes. Under certain conditions it is even possible to a draw current if there is a temperature difference at the sides of the Peltier Element.

The application for these extreme flat, small, wear-resistant, noiseless, and economical Peltier Elements are at locations where a good transport of thermal energy is essential and where conventional cooling- or heating-systems are too large, too noisy or not economical:

• miniature application of cooling- or heating-systems
• heat dissipation from hermetically sealed cabinets
• heat supply into hermetically sealed cabinets
• distribution of heat or cold
• spot cooling or heating
• temperature stabilization
• compensation of flow of thermal energy
• warming or cooling of objects
• in case of requirement for low weight in mobile applications
• in case of requirement wear-resistant continuous use
• in case no movable parts are desired

Thanks to its semiconductor construction the thermoelectric system in addition to above advantages shows a high reliability and therefore is ideally usable for scientific applications.

For optimization of temperature transition it is recommended to mount the Peltier Elements using heat sink compound with a thickness of 25 µm.

NTS, 1999