Frequently dryers are vented with a corrugated dryer duct of either a metal material or a type of nylon/plastic material. In our area these can be used for up to six feet in length in the same room. However for fire safety these types of dryer ducts of any length can not be run in concealed areas like in the attic or under the house.
Weekly we take photos of these types of dryer hose running often very long distances in attics or under the house. More often that not they are sagging or running downhill and uphill and may not even make out to the exterior of the house.
See an example below
Although this material is easy to work with this material often poses a fire hazard when used in the wrong areas, is too long or is improperly installed.
Easy is certainly not always the best way to go. Consult with an appropriate contractor for your area and install the proper materials for fire safety.
All the best out there.
