How Dryer Vent Fires Occur:
Lack of maintenance is the main cause, when lint builds up in the dryer or in the exhaust duct. Lint can block the flow of air, causing excessive heat to build-up, and result in a fire.

Symptoms:

A clogged dryer vent will cause excessive moisture in the laundry room and clothes take a long time to dry or won't dry at all. Sometimes birds build flammable nests in the vent too.

Benefits:

Cleaning the dryer vent will reduce the chance of a fire
Improve drying time
Increase energy savings by not having your dryer run as long

Process:

The vent pipe is removed from the back of the dryer and a powerful blower is attached to the vent. At the point where the vent exits the house, a 4" rotary brush is inserted and spun while the blower forces the loosed lint out of the vent pipe.