Paraffin wax is a perfect phase change material ( PCM) that can be used in latent heat storage units ( LHSUs) . The utilization of such LHSU is restricted by the poor conductivity of PCM. In the present work, a metal foam made of aluminium with PCM was used to produce a composite PCM as a thermal conductivity technique in PCM?LHSU and water was used as heat transfer fluid ( HTF ) . An experimental investigation was carried out to evaluate the heat transfer characteristics of LHSU using pure PCM and composite PCM. The study included time?dependent visualization of the PCM during the melting and solidification processes. Besides, a thermocouple network was placed inside the heat storage to record the temperature profile during each process. Results showed that better performance could be obtained using composite PCM?LHSU for both melting and solidification processes. The melting time of composite PCM?LHSU was about 83％ faster than that of a simple PCM?LHSU, and the percentage decreasing in the solidification time was about 85％ due to the provision of metal foam.