Chang Kuang wrote:
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,

It should not bend at all without crimping. That you should be able to
hold a five foot section horizontal and not have it bend or sag. It should
be smooth inside and out. That sounds like what you have.

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"?

It is harder for me to describe the flexible types. One is made from
the same material as the solid metal stuff, but is designed with angle
joints that when twisted will change a short (less than about a foot)
section to change from straight to a 90º bend and will hold that shape.
Both of the other two usually come labeled as vent hose and often sold for
dryer venting. They are just bent into shape or in the case of the really
light weight stuff will just fall into shape.

I don't like either of these for dryer vents. Both have the corrugated
interiors that reduce air flow and pick up lint. Neither is very fire proof
and sorry to say, fire is a possibility with a lint filled vent.


I am just curious how these two parts are connected together.

The solid stuff is crimped on one end and that crimped end slips inside
the end of the last pipe. In a dryer vent the crimp ends should always be
at the end away from the dryer. In some applications screws are used to
secure them, but for a dryer the screws will cause lint build up and they
should only be taped using real "duct" tape not duck tape.

The other stuff is often attached using some sort of clamp.

I hope that helps.

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

--
Joseph E. Meehan

26 + 6 = 1 It's Irish Math