The cold side temperature of the 6-stage TEC module under various heat exchanger configurations is depicted in Fig. 13. The heat exchanger configuration using water as the liquid coolant and equipped with a heat pipe without a fin, resulted in the lowest cold side temperature, indicating better heat transfer on the hot side of the module. The use of a heat pipe was proven to be effective in enhancing the heat transfer mechanism. However, the use of a fin with water as the coolant indicated a lower heat transfer performance.
Fins can be better justified under conditions for which the convection coefficient h is small, as in the case of air. In the case of a high convection coefficient such as water, the use of a fin will result in lower efficiency.