Lint that escapes through the lint trap can build up in the duct and narrow the passage of hot air outwards. This buildup causes inefficiency in your dryer’s operation, extends drying time and raises energy costs. Clogged dryer vent duct can become a fire hazard.
There are different methods for cleaning air ducts:
Negative Pressure Method
Negative pressure is a method in which loose debris is vacuumed out of the dryer vent. This is done through the connection point between the dryer and the duct.
Brushing + Negative Pressure Method
A brush is inserted into the duct via the connection point behind the dryer to loosen the lint from the walls of the duct. When the lint has been loosened, it is vacuumed out.