Abstract—Chiller barrel is considered as a shell-and-tube heat exchanger and generally applied in a water-cooled chiller. It is important to improve the performance of a chiller barrel so that the usage of electrical energy can be reduced while the quality of a product can be increased. In this project, the performance of a chiller barrel will be simulated and designing of chiller barrel being done based on the size of the baffle to improve the performance. Besides that, the flow characteristics of the fluid in the chiller barrel will be analyzed and compared by using a CFD simulation tool. Outlet temperature and pressure will be simulated while the rate of heat transfer, logarithmic mean temperature difference and overall heat transfer coefficient will be calculated. All value will be analyzed and selection the most optimum design which is the baffle with 30% of cut percentage based on the consideration of overall heat transfer coefficient and pressure gradient.