The he idea behind thermoelectric cooling (TEC) is that you can use energy to actively move heat from a cold place to a hot place. Generally, this isn't the case: the temperature in a room will reach equilibrium unless you do work (spend energy) to change that; if that sounds familiar, it's because it's a law of thermodynamics. A Peltier device is a cool (no pun intended) little gadget that facilitates this kind of cooling. When you send current through this white plate, one side becomes very cold and the other very hot.



Link: OCIA