What is the defferent between Aluminum Foil Duct and Semi-Rigid Aluminum Foil Duct
What is Aluminum Foil DuctMade of flexible aluminum foil, this is the most common type for dryer transition ducts — those that connect from the appliance to the main duct that runs to the outdoors. Foil duct can accordion from about 1 to 8 feet, which is usually enough for most installations. Double-check to make sure that this type is approved for your dryer and allowed by local code. Transition ducts must not be concealed inside walls or other building cavities and usually have a maximum allowed length of 8 feet. Foil duct is held in place with dryer clamps or large hose clamps. Metal tape can be used, too, but clamps make it easier to remove the tubing for cleaning.
What is Semi-Rigid Metal DuctSemi-rigid metal (usually aluminum) duct is flexible and similar to foil ducting but quite a bit more rigid. Like foil duct, semi-rigid is used only for transition ducting and should not be concealed in walls or floors. It is typically installed with clamps. Although semi-rigid metal duct is often stronger and has a smoother interior (catches less lint) than foil duct, it is more common to find listed foil duct than listed semi-rigid.