This study analyzes the thermo-fluid characteristics of the solar air heater duct (SAHD) consisting of W-shaped transverse ribs on the collector plate. The results of the study are presented with the appearance of Nusselt number, friction factor, thermo-hydraulic performance parameter (THPP), and contours of various fluid properties. Different roughness and flow parameters are considered for the computational study, like Reynolds number (Re) and nondimensional pitch (P/e). Re changes from 3800 to 18,000, and the nondimensional pitch changes from 7.5 to 18.75. The nondimensional height remains constant for the computational study. Aluminum was taken as the material of the absorber plate, and an isoheat-flux condition was employed on the plate with 1000 W/m2. The highest value of THPP obtained is 2.05 at P/e = 7.5 for Re = 12,000.