We recently had a contractor install a new unit (a Bryant Puron 2.5
ton in a 1500sq/ft 3br/2ba home) a couple of months ago. This week
we've had some really warm weather with temperatures in the 90s
nearing 100 degrees. The problem is the unit is not cooling the house.
The unit runs all day and doesn't drop the temperature below 78
degrees. Our older unit never had this problem.

We called the contractor that installed the unit out and he said that
was normal. He told us that these units won't cool more than 20
degrees below the ambient air temperature. He also said that the fact
that our ducts are in the celing makes this problem worse. Something
doesn't sound right here. I mean, our old unit cooled the house fine
and that unit was smaller (2 ton).

What's going on here? Is he correct, ignorant or simply lying? Can you
guys educate me on this? Should this unit be capable of cooling the
house better than it's doing now?