Our house was built in 1902 and we have restored rather than re-habbed.
That means no central A/C- it wasn't practical from a construction point of view.
So we have window A/C units in every room of the house. We just don't turn them on if we aren't going to be in that room. All of the 2nd & 3rd floor rooms have doors that we close off to save electricity. The 1st fl kitchen & LR are working most of the time.
I can't exist without them.