Abstract The Thermal and hydraulic performance of Double Flow Solar Air Heater (SAH) roughened with multiple C-shape rib was investigated experimentally. Three rib angles were used for different rib geometries with varying pitch distance, an angle of attack and Reynolds number. Multiple C-shaped ribs in double flow arrangement provides better heat transfer than other arrangements. Correlations were developed for Nusselt number, friction factor, Stanton number and Thermohydraulic performance parameter to increase the usefulness of result.