On our rental property, each of 4 units has an Armstrong Magic-Pak
"through-the-wall" combined HVAC system. They're 9 years old and haven't
always been cared for properly; the one in question is a new replacement
from January (heating died).
We had a 90 degree day here in Wisconsin, muggy and warm enough to
buckle highway concrete in Madison. The ceiling vent closest to our
tenant's HVAC has been dripping water. It's very clean, like condensate,
and doesn't seem to be in the drywall at all (that's cool but not damp);
it's coming right out of the ductwork and dripping through the vent
device. This duct is well above the AC unit which is at chest level, and
has exterior drip holes (which aren't dripping). The duct is on an
east-facing exposed wall, but one that doesn't really get direct sun
past noon or so. There's no nearby plumbing that I know of.
Before I rip out drywall, is this really just condensate? Why is it in
the ducts? The HVAC itself appears to be working properly.