On 9/29/2019 5:10 PM, Davej wrote:

The upstairs AC unit also suffers from the disadvantage of the
ductwork being in the unconditioned crawlspace attic.


If not already insulated, wrap it. Consider adding more if it is
insulated already.

For a proper diagnosis, use a thermometer in the duct to measure air at
the evaporator and at the end of the duct. You can see how much loss
there is.