Lint builds up in the vent with every drying cycle. If it is not removed, it restricts the exhaust of hot, humid air, which can cause the appliance to overheat and, in the most serious cases, lead to a fire.
A vent that is too long or poorly maintained does not always meet current safety standards. Beyond the fire risk, the appliance overheats, wears out its components faster, and uses more energy with every cycle.
