An improved theoretical model of a thermoelectric module is developed which takes into account both the electrical and thermal contact resistances. The model is used to investigate the effect of thermoelement length on the module＇s coefficient of performance (COP) and heat pumping capacity. The result indicates that the COP decreases with a reduction in the thermoelement length, while the heat pumping capacity increases until reaching a maximum. It is concluded that for a given short thermoelement length, significant improvement in both COP and heat pumping capacity can be obtained by reducing the contact resistances, particularly the thermal contact resistances.