variavel0=<b>Angelica Bouciguez</b> - bouciga@unsa.edu.ar INENCO. Universidad Nacional de Salta
<b>Luis Villa Saravia</b> - villal@unsa.edu.ar INIQUI. Univ. Nacional de Salta
<b>Sonia Esteban</b> - estebans@unsa.edu.ar INENCO. Universidad Nacional de Salta
<b>Miguel A. Lara</b> - malara@fceia.unr.edu.ar IFIR.Inst. Física. Universidad Nacional de Rosario
<b>Abstract.</b> The use of phase change materials in thermal conditioning presents a lot of applications, especially when it is exposed at variable temperature in the time. For that, the study of those substances has been though considering that the place to condition should be stayed at a fixed temperature, equal to the fusion one of the substance in use. To analyze the behavior of the phase change material to be used, a model of one phase Stefan problem was formulated, in which a consistent analysis is presented in a theoretical prediction providing existence and uniqueness of the solution and a numerical simulation using finite differences to calculate the free boundary position. The results show the behavior when the temperature varies at the time is similar at that in which the temperature is fixed and equal to the daily mead, It is useful because allows a simple evaluation of the interface position as a first approximation.
<b>Keywords.</b> phase change materials, variable temperature, thermal conditioning, free boundary position.