Abstractcompared to other storage materials. However, a vast amount of heat is generated during refueling of hydrogen in HPMH, where the heat will slow down or stop the absorption of hydrogen into the storage tank and causes a slow refueling time. Aside from heat generation, usage of heat exchangers for dissipation of heat in HPMH increases the weight and volume of the storage tank. In this paper, a prototype of heat exchanger design from a previous paper is revised, and a new prototype is proposed to improve the heat dissipation efficiency while achieving minimal space of heat exchanger in the system. Three prototypes of heat exchanger design are proposed, and the time taken for complete hydrogen absorption and the required space for heat exchanger are compared with the previous model. From the simulation results, two of the proposed models are proven to achieve a faster hydrogen absorption rate with a lower space area of heat exchangers.