A model for steam condensation in the presence of non-condensable gases is developed in the CFD package ANSYS CFX 16.1. Based on the Euler-Euler two-fluid approach, this model considers two different phases: a continuous gas phase, which is a mixture of air and steam, and a disperse liquid phase consisting of water droplets. Using the data of the CONAN test facility, the numerical error is quantified using the Grid Convergence Index method. The simulation results are then validated using the experimental data of the CONAN test facility. Finally, the applicability of the condensation modeling in the model containment THAI+ is tested.