Thermal performance of solar air heater found to be generally poor because of their inherently low heat transfer capability between the absorber plate and flowing air. Their thermal performance needs to be improved. Use of fins has been adopted by the researchers to improve the thermal performance of SAH. Their studies showed increment in thermal performance but fin optimization has not been addressed and optimization of fins parameters plays an important role in maximizing the thermal performance of collector. In this book single pass fin type solar air heater has been studied and optimized using CFD techniques to improve its thermal performance. During the study effect of air flow rate, number of fins, fin height, and fin length have been analyzed and CFD results are validated with experimental data.