Vortex induced non-Boussinesq laminar mixed convective heat transfer in a shrouded vertical non-iso-thermal fin array has been investigated numerically taking into account the variable transport properties. Computations are performed for the parametric range: Grashof number = 4.3-8.4 x 10(5), Reynolds number = 1280-2667, dimensionless fin spacing = 0.2-0.5 and dimensionless clearance = 0.0-0.25. Computations demonstrate inclusion of vortex generator results in a rise of pressure drop across the duct length to a value as high as 150% which is compensated by the substantial enhancement in heat transfer, as high as 200% locally and 20% globally compared to without vortex generator. Finally, overall Nusselt number is well correlated with the governing parameters of the problem. (C) 2014 Published by Elsevier Ltd.