<p>This study addresses the challenge of achieving uniform airflow distribution and minimizing pressure drop in fin-tube heat exchangers, where uneven flow can significantly influence heat transfer efficiency and overall system performance. To optimize header designs, computational fluid dynamics (CFD) simulations were conducted, evaluating models with varying port diameters, corner angles, and the inclusion of 2-stage perforated plates with and without reflectors. Increasing the corner angle of the header slightly improves the inflow velocity direction, however issues with longitudinal distribution persist. The 2-stage perforated plates effectively smooth out the airflow, resulting in more even distribution and enhanced overall efficiency. Additionally, the inclusion of reflectors helps distribute velocity more evenly, minimizing fluctuations. On the other hand, a smaller port diameter can lead to higher velocities and uneven distribution, increasing turbulence and recirculation, which reduces the consistency of airflow across the tubes. This study reveals that incorporating 2-stage perforated plates with reflectors significantly improves flow uniformity which achieved the lowest standard deviation of velocity profiles.</p>