The paper examines the possibilities of using simple CFD models in practical smoke ventilationdesign. The aim is to assess if it is possible with a reasonable accuracy to predict the behaviour of smoke transport in case of a fire. A CFD code mainly applicable for ordinary ventilation design is used for the examination. The CFD model is compared with benchmark tests and results from a special application fire simulation CFD code. Apart from benchmark tests two practical applications are examined in shape of modelling a fire in a theatre and a double faade, respectively. The simple CFD model uses a standard k- e turbulence model. Simulations comprise both steady-state and dynamic approaches. Several boundary conditions are tested. Finally, the paper discusses the prospects of simple CFD models in smoke ventilation design including the inherent limitations.