Entropy generation or irreversibility is forever present in the mass and heat transfer processes that takes place in heat exchangers. The performance of the thermodynamics of heat exchangers is degraded, and thereby useful energy is wasted. For this reason, extended research interest is attracted in order to minimize entropy generation in heat exchangers over the last three decades. This book Aims about tube row number of a direct expansion (DX) cooling coil to minimize the entropy generation in the DX cooling in the A/C system so that energy consumption is decreased is optimized. This is done by performing CFD and Thermal analysis. Tube row number 8 & 10 for varying air mass flow rates 0.3Kg/s, 0.5Kg/s, 0.7Kg/s, are investigated analytically. 3D models of the direct expansion cooling coils with different tube rows are done in Creo 2.0. CFD and Thermal analysis is performed in Ansys to determine optimal number of tube rows to minimize entropy.