On Friday, April 17, 2015 at 9:58:34 AM UTC-4, wrote:
I am not an air conditioner technician, however, I had a big problem with my new AC unit in my newly built 2450 square foot home in hotter-than-hell Texas not being able to keep my home at the 72F set on the thermostat. I had about 4 technicians tell me that the unit was working fine, but when the temperature kept creeping up approaching 80F, I called the manager of the AC company. He came out and just looked at everything, no tools involved. He told me that an AC unit, like a performance car engine, works better if you can improve the way it breathes. He advised me to add an additional air return duct and filter. I did this myself and all my problems were cured. A cheap and easy fix!

I presume this manager was from the same company that installed it?
I guess the only thing better would have been if the company put in
the additional return, which is what seems right. If they put the system
in a brand new house, it's supposed to work.....