Fan works, but isn’t providing good airflow

This can have several causes including the fan being in a poor location to the fan going in the wrong direction.

Having the fan set on the highest speed setting always gives the best airflow and should be used if you are looking for improved airflow. You want the fan to be turning clockwise during the summer and counter-clockwise during the winter (reversed). You should also make sure your fan generally follows the size suggestions listed in This Post.