An adaptive airflow flapper assembly may be configured to when present in a first chassis bay adjacent to a second chassis bay unpopulated with a another information handling resource module, close to a closed position relative to the enclosure such that, due to non-overlap of the enclosure airflow openings relative to the flapper airflow openings, the adaptive airflow flapper assembly prevents airflow between the interior and the exterior of an enclosure, and when present in the first chassis bay adjacent to the second chassis bay populated with the second information handling resource module, open to an open position relative to the enclosure to allow airflow between the interior and the exterior of the enclosure.