Designing an industrial calibration system that ensures fast and uniform cooling of a complex extruded profile is always a difficult task. Numerical tools are a valuable aid for the design of these systems in order to achieve fast, low-cost, and effective solutions. This work comprises the experimental validation of a numerical code, previously developed to support the design of profile extrusion calibration systems, using data collected from an industrial extrusion line. The referred numerical code was developed in the open-source computational library, OpenFOAM, being able to predict the heat exchanges between the polymer and the calibrator during the profile extrusion cooling stage. The good agreement obtained between the numerical code predictions and the experimental measurements allowed us to confirm the code accuracy. Subsequently, and in order to demonstrate the usefulness of the numerical code, a numerical study was carried out based on an optimization algorithm aimed at improving the performance of the studied calibration system. As a result, the study led to the proposal of an alternative setup, which presents a simpler constructive solution and a better performance than the existing one. POLYM. ENG. SCI., 2019. (c) 2019 Society of Plastics Engineers