Cold flow experiments with air and water as model fluids can make an important contribution to the characterization of column internals. They can be performed with comparatively low effort, however, on the other hand serve as an essential base for fluid dynamic model approaches, which in turn provide a bridge to technically relevant systems and operating conditions. In combination with other valuation methods, such as test mixture analyses or mathematical models, they can make a very important contribution to the safe and pinpoint design of column internals. Possibilities, but also limits of cold flow experiments are shown and related to tests with organic systems.