Air louvre arrangement suitable for being installed on a wall for separating two spaces

The invention relates to a ventilation flap arrangement adapted to be installed on a partition wall (11) separating two spaces, in an opening (10) passing through this wall. The arrangement is characterized in that it comprises a first module (3) adapted to be fixed on one face of the wall (11), around the perimeter of the opening (10), and a second module (5) adapted to be fixed around the perimeter of the opening (10) on the other face of the wall (11), and a movable cover (6) between a closing and release position of the opening (10), and in that the two modules (3, 5), in their fixed position on the wall, establish a passage through the wall (11), which is insulated from the internal surfaces of the opening (10). The invention is applicable in refrigerated vehicles.