Ayuh,... That's 24 sq. inches....I have determined the CFM exhaust I need for my bath to be 80; however with almost all baths, privacy with a closed door reduces the amount of airflow into the bath. My 24" door has a 1" opening at the bottom for airflow. I don't know how much air CFM this allows into the bath nor what the consequences are for my bath motor if this is insufficient.
Should I be concerned with this restricted air flow into the bath?
How much air ya gonna push through a 4" flex-vent tube,..??