A new hvac system is a joy to behold! We’re enjoying ours, too…

One thing I did in CA, and my sister does in AL, was to run a window unit in the room where I spent most of my time. In my case it was a 6K BTU unit in my office and my sister runs a 12K BTU unit in her living room/ kitchen area. I let the rest of the house drift to 85 during the day and only set the thermostat back down when I needed to use the rest of the house. The little unit in my office paid for itself in two months.

I foresee this arrangement becoming common in new houses, particularly with mini- split single room units. I can also see including more basements - ours is 5 degrees colder than the rest of the house both winter and summer.