Ventilation device for a space zone

A ventilation device, comprising an air propulsion plant (20) for supplying a space zone with displacement air and including at least one variable volume chamber (6) for conveying at least a portion of the displacement air in an air circulating mode in a pulsating manner;

• and at least one air passage (21) for connecting the variable volume chamber with the space zone for effecting both sucking of air into the chamber from the space zone and for expulsion of substantially the same volume of air from the chamber into the space zone.