Most homes we visit have never had the dryer vent cleaned before. Furthermore, the occupants are usually very suprised by how much lint comes out of their dryer vent. As the clothes spin around in the dryer they give off tiny peices of lint that flow throught he air and get deposited in the dryer vent. This lint is light, dry, fluffy and can be very flamable. As it accumilates in the dryer vent it can become a fire hazard over time.
We are frequently called to homes that have a partial or complete blockage in their dryer vent. This can be caused by wet lint settling in the vent and drying, creating a dam. It can also be caused by birds, bess,rodents or other animals getting into the vent and building a nests. Springtime is the peak season for birds moving in and building nests.
Once the vent becomes blocked the hot air from the dryer accumulates in it becuase it cannot escape. This raises the temperature in the vent and increases the lilkelyhood of the lint catching on fire.
The best way to prevent this fire hazard and keep your dryer functioning like it is supposed to is to have the dryer vent cleaned about once every year.