Peltier Cooler
Thermoelectric cooling via the Peltier effect — current pumps heat uphill
Peltier Effect: When current flows through a semiconductor junction (n-type + p-type), carriers transport heat from the cold side to the hot side. The Coefficient of Performance COP = Q_c / W measures cooling efficiency. For a single stage: Q_c = α·T_c·I − ½RI² − K·ΔT, where α is the Seebeck coefficient, R is resistance, K is thermal conductance. Stacking modules achieves greater ΔT but reduces total cooling power — each stage must also cool the waste heat of stages below.