A phase change device for the cold face of a Peltier pellet has been developed in this paper, as a substitute to the heat exchanger with aluminium plate with fins.

This device incorporates a porous material and the liquid inside goes up through it, evaporating and absorbing heat, to condense and return by gravity when getting in contact with the cold face of the Peltier pellet. This allows to increase the effective area of heat exchange, which is one of the main problems in the thermoelectricity development.

In its design theoretical studies with semi-empirical expressions have been done. Later, an experimental optimization has been carried out, through the construction and test of prototypes.

This device can be applied in any thermoelectric system for cold production, such as: refrigerators, air conditioned, dehumidifiers and so on.