said by iknow:109 here in Irving too. Our upstairs stays 74 and downstairs 72 during even those days. said by workablob:
It was 109* F here yesterday.
My upstairs unit could only keep it down to 76.
R50 in the attic, and a radiant barrier is the answer. unless you want to add a window AC for the hottest days. the expensive way is to change out your central AC for one with a thermostatic expansion valve, a variable speed blower, and at least a 2 speed compressor, a stepper motor compressor would be ideal. and have the unit oversized to handle those hot days.