The low value of convective heat transfer coefficient between the air and absorber plate is a major factor for low thermal efficiency of solar air heater. It can be enhanced by application of artificial roughness in solar air heaters. A serious of experimental work has been observed in literature shows that heat transfer rate increased by application of artificial roughness in the form of straight transverse ribs, inclined ribs, V shaped ribs either in full length or discrete, and combination of various ribs of different shapes. The results show that straight transverse ribs gives higher heat transfer rate than that of the smooth case in same flow and system parameters due to breaking of viscous sub layer and formation of turbulence. This paper covers a literature review of heat transfer enhancement by applying V shaped ribs in air flowing ducts. The results of V shapes ribbed ducts were compared with the smooth as well ribbed ducts on the same parameters. It is found that the angled ribs give higher heat transfer rate than transverse ribs, because of the secondary flow induced by the rib angle, in addition to breaking the laminar sub-layer and producing local wall turbulence. The results show that the V-shaped rib performs better than the angled ribs because of the development of two vortices cells compared to only one cell in the case of inclined ribs.