A thermoelectric module is a small solid state device that can operate as a heat pump or as an electrical power generator. When used to generate electricity, the module is called a thermoelectric generator (TEG). When used as a heat pump, the module utilizes the Peltier effect to move heat and is called a thermoelectric cooler (TEC). MELCOR is the world leader in TEC manufacturing. (Our products are also well suited for some TEG applications, however we address only TECs in this literature.)

The Peltier effect was discovered in 1834. When current passes through the junction of two different types of conductors it results in a temperature change. However, the practical application of this concept required the development of semiconductors that are good conductors of electricity but poor conductors of heat - the perfect balance for TEC performance. Today, bismuth telluride is primarily used as the semiconductor material, heavily doped to create either an excess (n-type) or a deficiency (p-type) of electrons.

If the current is reversed, the heat is moved in the opposite direction. In other words, what was the hot face will become the cold face and vice-versa.

The maximum amount of heat the largest single TEC can pump is about 125 W. So, you couldn't cool your house with it! However, our modular design enables you to use several TECs per application, allowing you to move more heat.

Sure! They can be used side-by-side to increase the amount of heat pumped, or they can be stacked on top of one another to increase the temperature difference across the TEC. When stacked, they are called "cascades", or multistage TECs. When the temperature difference between the hot and cold faces doesn't need to be more than about 60°C, single-stage TECs can normally do the job. If the temperature difference needs to be greater than 60°C, cascades should be considered. Some cascades are listed in the Multistage Specification table. Many others are available.

TECs are absolutely perfect for some applications and completely unsuitable for others. Depending on the application, a TEC can be much, much better than a compressor or no match at all. TECs are very small, very light weight, and completely silent. With no moving parts, they are extraordinarily reliable. TECs generate little, if any, electrical noise and can provide precision temperature control when used with an appropriate controller. They can be operated in a vacuum or weightless environments, and in any physical orientation. On the other hand, TECs tend to lose their competitive advantage when cooling loads exceeding 200W. Under some special circumstances, however, TECs are used to pump loads of tens of kilowatts.

Not really. It does require some understanding of heat transfer and a good grasp of your application. Selection/Performance graphs and an example are available here. Our Engineering Handbook explains in far greater detail how TECs work and how to select the one best suited for your application. Our experienced engineers are available to help you.

Proper installation is extremely important but not very difficult. MELCOR provides detailed, illustrated assembly instructions. And, we can build custom subassemblies for specific applications.

TECs are DC devices. The amount of heat pumped through the TEC is directly proportional to the power supplied. Temperature is controlled through manual or automatic means. The automatic controller can range from a simple on-off thermostat to a complex computer controlled feedback circuit. Such control systems are available from a variety of qualified manufacturers.