What kind of material is the vent made of? Is it flexible metal,
flexible foil covered material or solid metal? If it is anything other
than solid metal, time to replace it, even if it is not going to be easy to
do. It is not safe to leave the other stuff in service. A professional
should be able to replace it with minimal disruption to the walls.



Joseph,

The vertical part is pretty stiff, I guess that is what you mean by
"solid metal". The horizontal part is "wave-like" shiny aluminum from
what I see. Is that what you mean by "flexible foil covered material"?

I am just curious how these two parts are connected together. Probably
the top part of vertical solid metal part has extended horizontally
(like the rain gutter), and then run into the horizontal aluminum pipe,
which has a bigger caliber.

Thanks,
Chang