Thermoelectric cooling works by using an electrical current to move heat from one side of a semiconductor device to the other through the Peltier effect. When current flows, heat is absorbed on one side of the device (the cold side) and rejected on the opposite side (the hot side). The amount of cooling depends on the cold-side temperature, material properties, electrical current, ambient conditions, and how effectively heat is removed from the hot side.

A thermoelectric cooler (TEC) uses electrical power to move heat from one side of a device to the other for cooling or heating. A thermoelectric generator (TEG) operates in reverse, converting a temperature difference into electrical power. In many cases, the underlying hardware is similar, but the operating mode and system design are different.

In real systems, thermoelectric cooling performance is often limited by misaligned expectations, poor system design, and mismatch between the thermoelectric module and the application. Underestimated thermal interface resistances, ineffective heat rejection, and improper electrical operating conditions can significantly reduce performance. All of these factors must be aligned to achieve expected results.