Clogged dryer vents are dangerous because they can start house fires. In addition, lint build-up inside a dryer vent can cause the dryer to work less efficiently. Dryer vents should be cleaned at least every two years by manually removing large obstructions and vacuuming away any residue./
Unplug the dryer, and pull it out from the wall. Vacuum up any dirt behind the dryer.
Detach the dryer hose from the wall. Insert a lint brush with an extendable handle into the dryer vent. Move the brush around, pulling it out and removing lint until no more lint comes out.
Wearing work gloves, open the dryer vent cover on the outside of the house. Look into the vent before you stick your hand or a lint brush into it. If you see any stinging insects, such as bees, call an exterminator before you try to clean the vent.
Extend the lint brush, and put it into the dryer vent. Move it around to gather lint. Vacuum the opening of the vent with a shop vacuum.
Wash the vent cover with dishwashing soap, then use it to close the vent on the outside of the house. Reattach the dryer hose to the wall. Push the dryer back into place.