This experimental and numerical study investigates the effect of porous media on the thermal storage behaviour of a refrigeration duct system. The study presents the transient behaviour of heat absorption and Nusselt number for different velocities and porous media presence/absence cases. Results show that the heat transfer rate decreases over time, with the presence of porous media, providing resistance to heat absorption, particularly at relatively low velocities. The Nusselt number decreases slightly over time, but it increases as the velocity increases in all cases, with the maximum value observed at a velocity of 3 m/s. The presence of porous media significantly enhances heat transfer, with an improvement of up to 150% at a lower velocity of 1.5 m/s and 110% at an inlet velocity of 2.25 m/s. The study provides a comprehensive visualisation of the heat transfer process through contour analysis of temperature distribution, allowing better understanding of the thermal storage system’s design and performance. The findings have implications for the optimisation of thermal storage systems in various applications, including energy-efficient buildings and renewable energy systems.