Thermoelectric cooling

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Thermoelectric cooling uses the Peltier effect to create a heat flux between the junction of two different types of materials. A Peltier cooler, heater or thermoelectric heat pump is a solid-state active heat pump which transfers heat from one side of the device to the other side against the temperature gradient (from cold to hot), with consumption of electrical energy. Such an instrument is also called a Peltier device, Peltier diode, Peltier heat pump, solid state refrigerator or thermoelectric cooler (TEC). [[1]] Because heating can be achieved more easily and economically by many other methods, Peltier devices are mostly used for cooling. Although, when a single device is to be used for heating and cooling, a Peltier device may be desirable. Simply connecting it to a DC voltage will cause one side to freeze, whilst the other side heats up. The effectiveness of the pump at moving the heat away from the cold side is totally dependent upon how well the heat from the hot side can be removed. They can also be used to generate electricity (thermogenerator) if a temperature difference is maintained between the two sides. Peltier devices are commonly used in camping and portable coolers and for cooling electronic components and small instruments. The cooling effect of Peltier heat pumps can also be utilized to extract water from the air in dehumidifiers. There are no moving parts and such a device is maintenance free. Due to the relatively low efficiency, thermoelectric cooling is generally only used in environments where the solid state nature outweighs the poor efficiency. Thermoelectric junctions are generally only around 5-10% as efficient as the ideal refrigerator (Carnot cycle), compared with 40-60% achieved by conventional compression cycle systems (reverse Rankine systems like a compressor).

1 Performance
2 Uses
3 External Links
4 See also

[edit] Performance

Peltier (thermoelectric) cooler performance is a function of ambient temperature, hot and cold side heat exchanger (heat sink) performance, thermal load, Peltier module (thermopile) geometry, and Peltier electrical parameters. Online Peltier (thermoelectric) cooler performance calculators from companies such as Novel Concepts, Inc., can accurately estimate Peltier cooler performance.

[edit] Uses

The effect is used in satellites and spacecraft to counter the effect of direct sunlight on one side of a craft by dissipating the heat over the cold shaded side whereupon the heat is dissipated by radiation into deep space.

Thermoelectric coolers are also used to cool computer components to aid overclocking. Used in conjunction with a heat sink or waterblock, Peltiers are capable of cooling a chip below ambient room temperature.