What is Lint?
Fine cellulose and synthetic fibres released as fabric tumbles. The lint screen catches most of it, but a meaningful fraction passes into the exhaust duct on every cycle and settles where the airflow slows — at elbows, at the base of vertical rises, and behind the exterior damper. It is dry, has enormous surface area for its mass, and sits in the path of a heat source, which is why accumulation is treated as a fire-risk issue rather than a housekeeping one.
