Central AC Troubleshooting

I live where there are many 100 plus days in the summer (spring and fall too). And I work at home. HVAC is absolutely essential to my job and non-job comfort. I spend $200 a year, $100 in the spring and $100 in the fall to have HVAC pros come out and inspect everything. The system is way too expensive and necessary to not take care of.

Nit pick. In engineering terms Delta T is the temperature difference between two different measuring points.
Inside vs outside
Inlet Vs outlet or exhaust
supply VS return

Bingo we have a wise winner here

Except for the fact that he chooses to live in a place like that.