A thermoelectric cooling module or Peltier module is a building block for construction of thermoelectric cooling systems. The COP and the cooling capacity of the module may be estimated using the conventional module theory based on one-dimensional heat balance equations, in which the thermal and electrical contact resistances are neglected. The COP derived in the conventional module theory is determined by the hot and cold side temperatures of a module and the figure of merit of thermoelectric material but not by the length of a thermoelement. Hence, it cannot be used to optimize the length of a thermoelement. Min and Rowe developed an improved model which took into account both the thermal and electrical contact resistances. Their model provides a better accuracy for modeling of thermoelectric cooling modules and proves to be very useful in analysis and optimal design of small dimension thermoelectric cooling modules. Pettes et al. extended the conventional module theory to account for the thermal and electrical contact resistances. They provided a procedure to calculate the optimum thermoelement length which maximizes the cooling capacity or the COP at a specified cooling capacity