Solar energy constitutes one of the main alternatives for facing the energy problems of the future. Solar air heaters are used for applications at low and moderate temperatures. Such as crop drying, timber seasoning, space heating, and drying agriculture products. Artificial geometry applied on the absorber plate is the very efficient method to improve thermal performance of solar air heaters. The thermal efficiency of solar air heaters is generally poor due to low heat transfer coefficient between the absorber plate and air flowing in the collector. Thermal performance of the conventional solar air heater was studied under varying solar and ambient conditions in different months. At day time the solar heating system stored the thermal solar energy as sensible and latent heat. A parametric study was done for 10 months for the climatic conditions of Visakhapatnam. The effect of change in the tilt angle, length and breadth of a collector and mass flow rate on the temperature of collector has been studied. The length of the collector is 2.1m and width of the collector is 1.1 m. the performance analysis of system shows potential of improving the thermal efficiency range is 31% to 47% .From the obtained results, graphs are drawn to assess the performance analysis of a conventional air heater.