This paper presents the results of an experimental and numerical study on the solidification of different phase change materials (PCM) encapsulated in spherical and cylindrical shells of different materials and diameters subject to constant surface temperature. The main objective is to determine the time for complete solidification of the PCM and how it is affected by the variations of the surface temperature, material and diameter of spherical shells. As a result of the study, it is expected to define a pair of container and PCM to operate adequately and efficiently together with refrigeration units. The experiments were realized using glass and plastic spherical shells of diameters 0.035, 0.076, 0.106 and 0.131 m, soft drink cans and small plastic water bottles with surface temperatures of -5, -10, -12, -15, -18, -20 and -25 degrees C. The phase change materials used are water and mixtures of water with 3.75%. 7.5%. 15%. 25%, 30%, 40% and 50% Glycol content. The results are presented and discussed. (C) 2009 Elsevier Ltd. All rights reserved.