In this study, the latent heat thermal energy storage system of the horizontal shell-and-tube type is experimentally analyzed. Paraffin is used as the phase change material (PCM) while the distilled water is used as the HTF. At first, the thermo-physical properties of the paraffin used are determined through the differential scanning calorimeter (DSC) analysis. Experiments are conducted to investigate not only the storage behavior (melting or charging) but also the removal one (solidification or discharging) of the PCM. Effect of the inlet temperature on the melting (for the charging) and solidification (for the discharging) time is determined. The focus is on the understanding the physics of the process based on the temporal variation of temperature field inside PCM. (C) 2013 Elsevier Ltd. All rights reserved.