An overview of the parameters affecting the coefficient of performance of thermoelectric cooling

Thermoelectric systems have many advantages, including environmentally friendly, without noise and high reliability. Due to the reduction of fossil fuel resources and emissions resulting them, using of thermoelectric systems both of cooling and generator are increasing. But one of the main disadvantages of thermoelectric cooling is low coefficient of performance. Today, researchers have a particular focus on the coefficient of performance and are trying to improve it. To learn more about the coefficient of performance parameters that are discussed in this paper to review. For this purpose, the first effects of electrical contact resistances and thermal resistances are investigated at small thermoelectric modules that by ignoring it will not reach the desired results. Also, by decreasing the electrical contact resistance can increasing the coefficient of performance 50 to 60 percent. Then correlation between the coefficient of performance and thermoelement length, temperature difference and electric current is provided. Finally the multi-stage modules has been discussed as a result of increasing stages, coefficient of performance also increased.