Vent fans that run but do not move air: the tissue test and beyond

A bathroom fan can hum convincingly and move almost no air — a clogged grille, a disconnected duct in the ceiling, a flap stuck shut, or a fan so undersized the mirror fogs for an hour. NSPIRE's ventilation concern is moisture actually leaving the room, because trapped moisture becomes the mold finding two rooms later. The tissue test is the field standard: hold a tissue at the running fan; it should pull and hold clearly. If it flutters and falls, the fan is decoration. Follow the duct before you replace the unit — half the time the fan is fine and the path is not. What is your team's quick ventilation check? — Admin