Patent ID: 7586742

Claim:
A heat dissipation module, comprising: a first heat dissipation apparatus having a first housing, a first impeller having a first axis, a first airflow passage disposed in the first housing and a plurality of first flappers disposed within the first airflow passage, wherein a long side of the first flapper is perpendicular to the first axis; and a second heat dissipation apparatus having a second housing, a second impeller having a second axis, a second airflow passage disposed in the second housing and a plurality of second flappers disposed within the second airflow passage, wherein a long side of the second flapper is perpendicular to the second axis; wherein the first flappers and the second flappers are moved to an open position due to force generated by air flowing through the first airflow passage and the second airflow passage, and are moved to a closed position after the force is removed, wherein each of the first flappers overlaps an adjacent first flapper to seal the entire first airflow passage of the first heat dissipation apparatus and each of the second flappers overlaps an adjacent second flapper to seal the entire second airflow passage of the second heat dissipation apparatus; and the first housing and the second housing are disposed in a mirror-image arrangement.