This paper describes the modeling of typical secondary air system elements such as rotating orifices, seals, and flow passages with heat and work transfer from the surrounding surfaces. The modeling is carried out in an object-oriented simulation environment that allows the creation of different configurations in a simple and flexible manner. This makes possible to compare the performance between different designs of individual components or complete secondary air systems as well as integrate them directly in whole engine performance models. The modeling is validated against published experimental data and computational results. An example of implementation in an engine model is also presented.