I'm doing handyman work for a client in a small cape cod style house. We've discovering several things that were done wrong or half-baked throughout, so it wouldn't surprise if the AC is also as bad as it appears at first glance.

I'm no AC expert, but was wondering about a couple observations. For lack of a better description, the air handler has two PVC "ports" installed on the front/top of the cabinet. One is just a short stub, and an adjacent one extents w/ 2" PVC up and out (about 12 feet), through a rim joist and terminates into a crawlspace under an addition. (Still with me?) Is there ever a reason for PVC in a situation as I describe?

BTW, as for the supply and return, they used insulated flex throughout. They have one return on the second floor, zero on the first floor (ducts pass through a closet but no duct openings, yet there happens to be a 24"x24" grill installed in the closet wall).

The only other return is right outside the air handler closet.

What do you think about this set-up?