Thermoelectric systems are solid-state devices that directly convert electrical energy into temperature differential without the use of gases, compressors or any other moving parts.
A standard thermoelectric system consists of:
- Cold side and hot side heat sink assemblies with or without fans
- Thermoelectric (Peltier) cooling modules
- Temperature controller
- Power supply
The only moving parts are fans, which make thermoelectric systems more compact, reliable and quiet relative to conventional compressor based cooling systems.
A basic element of the thermoelectric system is the Thermoelectric Module (TEM), which actually operates as a heat pump.
The TEM is a solid-state semiconductor device made of two thin ceramic plates with a large quantity of semiconductor elements sandwiched between the plates.
Two types of semiconductors, P and N types, are used in the module. They are connected electrically in series and thermally in parallel in such a way that all cold junctions are placed on one plate and all hot junctions on the opposite plate. Electrical current passing through the junctions absorbs heat energy on the cold junctions, which is then dissipated on the hot junctions.
To ensure the TEM’s cooling performance, the heat energy should be efficiently dissipated from the hot plate to the surrounding atmosphere.