One of the most promising materials for storing thermal energy and using that energy for cooling applications is phase change material (PCM), although PCM is not as readily available or inexpensive. This study focuses on an experimental examination of incorporating Lauric acid (LA) as phase change material (PCM) above the absorber surface to improve the performance of a solar air heater (SAH) system. To evaluate the effectiveness of adding LA, the performance of the modified system improved SAH is compared with that of a conventional system traditional SAH under identical operating conditions. In the improved SAH model, LA is integrated above the absorber plate, while the traditional SAH model represents the traditional setup. Data was collected in Mosul City, Iraq, during 10 and 25 December in 2024 and 15 January in 2025, with experiments conducted at a constant air mass flowrate 0.02223 kg/s. The results demonstrate that the improved SAH model outperforms the traditional SAH model by 100, 100.5, and 55.5% in while for traditional SAH through 10 and 25 December in 2024 and 15 January in 2025 are (70%, 62%, and 90%) respectively. Additionally, the findings reveal a significant maximum temperature difference achieved by the improved SAH model compared to the traditional SAH model.