Research on turbulent mixed convection flows is of considerable interest for many technological applications. While solving the Reynolds-averaged Navier-Stokes (RANS) equations is nowadays common practice for industrially relevant turbulent temperature-driven flows, more accurate results can be obtained by applying the computationally more expensive large-eddy simulation (LES) technique. The objective of this work is to test and develop subgrid scale models for LES of mixed thermal convection in geometrically complex domains, which are typical for applications in the aerospace industry. Emphasis will be placed on evaluating the heat transfer capabilities of various subgrid scale models with well-documented test cases before applying them to industrially relevant real-world configurations, e.g., thermal flows in aircraft passenger cabins.