Installation of new dryer vent. Clogged clothes dryer vents increases drying costs and shortens the life of your dryer. When lint accumulates in an exhaust duct, it reduces the dryer’s ability to expel heated water vapor causing heat energy to build up within the machine. As the dryer overheats, mechanical failures can trigger sparks, which can cause lint trapped in the dryer vent to burst into flames. Fires generally originate within the dryer but spread by escaping through the ventilation duct, incinerating trapped lint, and following its path into the building wall.