The application of a phase change material (PCM) as thermal energy storage observed unprecedented growth due to its large latent heat storage capacity at a constant temperature. However, the design of an energy storage heat exchanger is a challenging task because of the poor thermal conductivity of PCMs. In an effort to improve the heat exchanger design, this paper presents a numerical performance investigation of a PCM-based multitube heat exchanger incorporated with two new fin configurations. The analysis of the results shows that the placement of fins is one of the important aspects, which needs to be cogitated in the design of heat exchangers. © 2017 Taylor & Francis.