On Sat, 28 Sep 2019 09:11:30 -0700 (PDT), Davej
wrote:

I hate to interrupt the ongoing political trolling but...

If an HVAC system was "appropriately" sized, what maximum duty
cycle should be seen? In other words if my upstairs AC runs
continuously -- that probably means it has a problem or is
undersized. But then, if it was working correctly and was properly
sized -- what duty cycle range would you expect? Thanks.

A perfectly sized A/C unit would run continuously on the hottest day
in the design criteria to maintain the design inside temperature.