Metal foam has found its way in many engineering industries due to its ability to improve the heat transfer rate in thermal applications. Thermal energy storage based on phase change materials (PCMs) have significant importance as a part of renewable energy sources, and thermal management applications, However, low thermal conductivity is the essential drawback associated with the PCMs, especially the organic type of it, such as paraffin. Various experimental and numerical studies performed to test the effect of using metal foam with PCMs, in order to improve PCMs thermal conductivity. Many models suggested for evaluating the effective thermal conductivity of high porosity open cells metal foam, which immersed in base fluids of low thermal conductivity such as air, water, and PCMs. This work achieved numerically by using different models for calculating the effective thermal properties of metal foam with various range of porosities impregnate in paraffin. The study discussed the temperature distribution, which control the heat transfer rate, the behavior of temperatures versus time, and improvements in the melting front phase of the paraffin, under the effect of copper metal foam of various porosities and by applying different models, for estimating the effective thermal conductivity. The results exhibit an augmentation in the effective thermal conductivity with porosity decreasing. The outputs showed paradoxical results using the presented models and the differences between them have been discussed.