I have a question about airflow with a bathroom fan, in this case a Ventaxia VASF100T with a front cover, duct through the wall and a gravity grille on the outside.
It seems quite inefficient at clearing steam, and I am wondering if the exterior vents are just stopping air from moving outside? What I am referring to is called a "gravity grille" I would have expected the flaps to open when the fan is on but I have checked and they do not move at all. How can air be pulled outside if there is something blocking it? Maybe the air is just recirculating..