This paper aims to employ and study the effect of passive cooling techniques in the reservoir section for liquid cooling systems. The reservoir section is modeled as twodimensional cavity with hot fluid entering from the top with an exit near to the bottom wall. The passive cooling in the reservoir is studied using a porous media-filled cavity with a cold bottom wall. A laminar generalized porous media modeling approach using Brinkman's and Forchheimer's terms has been used. The effect of varying porosity, Darcy number, and multiple inlets on the percentage reduction in outlet temperature with respect to the inflow conditions has been studied. Results indicate that porous media with a cold bottom wall in the reservoir section can significantly improve cooling, making it a valuable addition to closedloop liquid cooling systems. A maximum reduction of 9.845% has been reported.