Mike, here's a view of the other side of that unit.

The "hose" is a piece of sealtite that starts at the first "bell" box (see the 90 fitting on the end?), passes through a gap under the duct, attaches to a vertical piece of pipe (not visible), then returns to sealtite ... seen in this pic flying through the air, with but an unusual assortment of fittings in the middle!

[Linked Image]


Here's a closer look:


[Linked Image]