My new SEER30+ mini-split air conditioner has been operational for a few days now. I’ve been running it at night with my central air conditioner off. It’s difficult to say how much impact that has had in increased efficiency, but there is no doubt it has to have contributed greatly. Other factors to be considered are cooler temperatures and cloudless days. Looking at the percentage of electricity from my solar panels over the last ten days, and considering that these are the shortest days of the year, I can only conclude that it seems to be a big step in efficiency for my house.