A new methodology is presented to calibrate the 1D CON1D model with a full 3D finite- element model of the mold. Coupled with models of solidification and interfacial phenomena, this modeling tool is applied to gain insights into many aspects of heat transfer in the process. The CON1D model is based on a 1D finite-difference solidification model of the shell, taking advantage of the large Péclet number that makes axial heat conduction negligible relative to heat transported by the moving steel. It includes conduction and radiation across the interfacial layers, aided by mass, momentum and force balances on the slag, which are all solved analytically. Simplifying the mold geometry for the 1D model requires careful definition of the dimensions in order to retain the thermal characteristics of the system. This calibration of the thermocouple location should be performed after the water channel geometry has been calibrated.