A ventilation diffuser bag for disposition on a vehicle occupant support includes a perforated, occupant facing side and an opposite non-perforated, support surface facing side. The non-perforated side includes an opening to allow air flow into the diffuser bag. An air mover support integral with the non-perforated side includes an endless sidewall extending from the opening for providing support for an air mover. The endless sidewall includes a retaining edge spaced from the non-perforated side for suspendably retaining the air mover within the air mover support. The non-perforated side of the diffuser bag is supportable on an occupant facing surface of a vehicle occupant support, and the air mover support extends into the occupant support.