EXPANDED ALUMINUM FLEXIBLE VENT TUBING
Thought one was doing the proper and good thing by chucking the white "plastic" in favour of the semi-flexible metal for my vintage Whirlpool portable dryer. Am now having serious second thoughts.
No matter how hard and fast one clamps the darn thing to the dryer vent opening, it manages to come loose sooner or later, especially if one often extends and contracts the hose. Since my unit is portable and not often used, it sits in a corner until required, then rolled to the nearest window, hose extended, and end inserted into a window vent, etc...
Just as the above poster stated, the end affixed to the dryer opening becomes squashed down from being reattached so often, and it rarely fills all the way out again.
Methinks the vinyl hose for a portable shouldn't be that bad if one changes for new often, or uses one of those hose/vent cleaning kits to flush things out. Many hardware stores sell all sorts of dryer venting by yardage, cut to measure, or simply scout around eBay; there are always cheap kits on offer there.