In order to prevent entrainment, an air curtain should provide a jet with low turbulence level, and enough momentum to counteract pressure differences across the opening. Consequently, the analysis of the discharge plenum should be taken into consideration. Hence, the main object of this paper is to study the discharge chamber geometry and the presence of blades for ?ow orientation. This analysis is carried out in order to understand their in?uence on the jet produced. Studies presented are based on detailed numerical simulations and on experimental measurements. The in?uence of the turbulence model, boundary conditions and computational domain is investigated.