Rigid vs Flexible Dryer Vent Duct: Which to Use

For a dryer vent, use smooth-wall rigid metal duct. Ribbed flexible duct, especially the foil or plastic kind, traps lint in every ridge, sags into low spots that collect moisture, and kinks at corners, all of which slow drying and raise the risk of a lint fire.

Why rigid duct dries faster and safer

A dryer has to push hot, moist, lint-laden air all the way outside. Smooth rigid metal gives that air a clean path, so the dryer exhausts quickly and lint carries through instead of catching. Ribbed flex does the opposite: every corrugation grabs lint, the airflow drops, and the dryer runs longer and hotter to do the same job.

What to check

• Concealed runs in walls or floors should be smooth rigid metal duct, not flex.
• Any flexible connector at the dryer should be short, UL-listed semi-rigid aluminium, never thin foil or plastic.
• Joints should run in the direction of airflow and be secured with foil tape or clamps, not screws that poke into the airstream and catch lint.
• The run should be as short and straight as the home allows, ending at a proper exterior vent hood.

Common mistakes

• Long runs of cheap foil flex stuffed behind the dryer and crushed against the wall.
• Sheet-metal screws at the joints, which snag lint and start a clog.
• Plastic flex, which is both restrictive and flammable.

When to call a sheet metal contractor

If your dryer takes more than one cycle, the duct is hot to the touch, or the run is long, kinked, or buried in flex, it is worth rebuilding in rigid duct on a shorter route. That is straightforward work that pays off in faster drying and lower fire risk.