This paper deals with the elaboration and the validation of a userfriendly numerical program (EOL) for the calculation of the ventilation patterns inside industrial premises. After the running-in. In period, "EOL" will be used by the technical staff in charge of ventilation projects. Here is set out the EOL unit devoted to the calculation of the mean flow inside the rooms. The structure of the software (presently restricted to two-dimensional mean flow configurations) is explained. The experimental validation of the software is performed through the use of a test configuration set inside an hydraulic bench. The measurements of the mean flow inside the plexiglass scale model are done by a Laser Doppler system. For two characteristic profiles inside the measuring section, experimental and numerical results are compared. Very fine agreement is obtained. This result is quite encouraging for the development of the EOL programming operation.