Heat transfer characteristics during crystallization and melting of the phase change material (PCM) dispersed inside an emulsion are investigated theoretically and experimentally. The dispersed PCMs are hexadecane, octadecane and water. The crystallization and melting processes are not symmetrical because of the supercooling phenomenon induced by the smallness of the emulsion droplet sizes. Nucleation laws are used to simulate the supercooling phenomenon. Energy analysis is carried out to understand the behavior of the emulsion using two paraffins (octadecane and hexadecane). The effects of different parameters such as the mass fraction of PCM and the stabilization temperature on thermal behavior of emulsion are also analyzed. (C) 2011 Elsevier B.V. All rights reserved.