In this work, we present an experimental and numerical study of a turbulent jet from a lobed diffuser, applied to residential comfort. The main aim is the improvement of the air diffusion efficiency, of the ventilation driving flow in the occupancy zone, with least cost. The experiments have been conducted in a room where the dimensions enable a better execution in the conditions of free and hot vertical jet at unfavorable pushing forces. The room has been isolated from the environment during experiments. The temperature difference between the jet and the environment has been controlled by readjusting the blowing jet temperature. Consequently, the jet's Archimedes number is kept constant during tests. The installation includes a hot air blowing diffuser oriented from top to bottom. The temperatures and velocities of the flow have been measured by a multi-functional thermo-anemometer. The probe is supported by a stem that is guided vertically and horizontally in order to sweep a maximum space. The numerical study has been carried out using the Fluent code (V.6). The numerical results obtained with the turbulence model (RNG k-ε) turned out to be in a good accordance with the experimental results.