So whats the answer already?
What's the answer!!??
It looks like some small, condensating ductwork that is piped down at 1/8" per foot into the house to me
I like the grade A set up of that black wire...
Would it be that the return air duct has no poopie on the seams? So its leaking through the return air vent?
There is no "T" after the P-trap, the unit does not drain when it's humid, and the condensate overflows into the Return. It then follows all that nice long, waterproof Return ductwork into the home. Fun fun.
Who uses adjustable elbows and snap-lock pipe on a roof?
Why is an air vent required after a P-trap?
Not knowing that is exactly why -- over the years -- I've had to fix so many water leaks on other people's installs.
I've done it myself. I once installed a 10-ton Trane split in a warehouse and forgot to put a T after the p-trap. The unit won't drain. We flooded the warehouse. Luckily eveyrthing was up on palettes
-- think of a straw in a glass of water. Put your thumb over it. Pick it up. Why doesn't the water drain? Negative air pressure is stronger than the weight of the water.
In the case of an A/C -- the blower creates the negative pressure in the straw (PVC drain line).
I can't tell you how many water damaged homes I've seen due to the lack of an air vent after a trap. Or, if you put the air vent before the trap, the unit won't drain either. Or, if you don't put a trap or an air vent at all.
Every plumbing fixture in your house has or shares an air vent that sticks up out of the roof, so they can drain. Otherwise the water would stick in the pipes and not drain, against the laws of gravity.
Common problem here.