Abstract Experimental and numerical analyses were conducted to compare the charging and discharging performance of an ice-on-coil latent thermal energy storage tank (LTES). We examined the effect of three parameters: (1) orientation of the tube arrangement (horizontal or vertical), (2) tube diameter (10A or 6A tubes), and (3) tube outlet location (on tank top or tank bottom). Experimental observations had to be confirmed because not only the tube orientation, but also the tube outlet position could have caused a difference in performance. This uncertainty was assessed using numerical analysis. The results show that thermal stratification in molten phase change materials (PCM) plays an important role in charging and discharging performance, and that this performance is different depending on the tube orientation. Thus, the cases when the tube outlet was located on the top of the tank and when the tube orientation was horizontal showed the worst discharging performance. This difference increased with tube diameter.