This study presents a numerical investigation of the thermal performance of a U-bend tube ground heat exchanger (GHE) with paraffin wax as the phase change material (PCM) using ANSYS Fluent R1 2020. Using a U-tube instead of the straight tube results in the same or increased surface area at the reduced pipe length which further lowers the initial cost associated with GHE construction. Though there is a handful of studies regarding the performance enhancement of GHE, studies related to GHE with PCM, particularly fitted with a U-tube are inadequate, The GHE was constructed with a double U-shaped pipe, buried 45 meters underground, and the borehole was filled with paraffin wax as PCM due to its availability, steadiness, corrosion resistance, non-toxicity, and high latent heat capacity. The governing equations in this study are solved by the Realizable k-ε turbulence model. Air was circulated at velocities ranging from 0.5 ms-1 to 5 ms-1 in increments of 0.5 ms-1 for 12 hours to explore the system's performance, with an inlet temperature of 309 K in all cases. Upon increasing the velocity from 0.5 ms-1 to 5 ms-1, it was found that at 12 hours of operation, the mean rate of heat transfer per meter increased from 76.27 Wm-1 to 116.45 Wm-1, thus the highest velocity exhibiting a 65.5% increase over the lowest, while the temperature drop decreased as velocity increased, ranging from 9.09 °C at 0.5 ms-1 to 7.2 °C at 5 ms-1. When it comes to effectiveness, initially for all air velocities the system's maximum effectiveness was found to be between 64% and 61%. After 12 hours, effectiveness dropped to 47% at 0.5 ms-1 and to 37% at 5 ms-1 demonstrating that effectiveness reduces over time and at lower velocities the system is more effective. Moreover, it was also found that after 40 meters of GHE, there was a minimal temperature change, thus using GHE beyond this length gives insignificant thermal benefits. This necessitates future research on finding the optimal length for GHE, focus should also be given to improving performance under various environmental conditions, design optimization, and thermal performance improvement, using phase change materials to reduce initial costs.