For my air conditioning I have a split ductless system, otherwise known as Mr. Slim. I run my A/C constantly all summer long. I might have cracked a $50 electric bill once or twice during the Summer, but only when it’s really hot for a long time.
Both rooftop AC units were stretched far beyond their expected life spans when I replaced them last year. I REALLY wanted to replace one of them with mini splits. I’m certain they would have saved a lot on electricity. Un(?)fortunately, after obtaining nearly a dozen different bids, I got a deal so sweet on a pair of heat pumps that I couldn’t justify going any other way. I will say the electric bill did drop with the new units.