If your dryer vents under your home, you're filling that area with lint. Lint is highly flammable! If it's not wet and full of mold.
Another huge problem with dryer is vents is using the correct type of dryer vent. It should be rigid metal dryer duct. The plastic and aluminum colored plastic, should never be used. It should always be vented to the outside of the home.
Like Yanita mentioned, Mark has an excellent article on this subject!
Maureen
