I have got central a/c. It is roof mounted, as most ac units are out here, to increase efficiency. When its 118-120 degrees outside, it keeps the house about 78 degrees - but only because of proper attic venting and window screening. 3 14" ventilators help vent 150 degree attic air and take several degrees off the room temperature. Solar block screening helps protect heat transfer from the glass areas of the house. When it's just 104-105 (which out here is merely 'warm')it can keep the house a very nice 74 degrees.

I have a 12,000 btu wall mounted garage a/c (mounted six feet up to maximize the cool air flow) but it can only get the garage to about 88 degrees on a day like today. Not too comfortable, but far better than an unconditioned 125+ degrees though!

In California, I had a former model home which had installed an industrial strength TRANE a/c unit. When it was 103 in late August/ early September that baby could get the house down to 66 degrees without even trying. It got so cold, one had to make sure the thermostat was set for 72 and not lower. You never even knew it was warm outside until one opened the door. Now that was an a/c! I wouldn't want to guess what electric charge$ that unit generates today. ;-)

All my experience from living without a/c comes from sustained power outages and the seemingly interminably long days between a/c unit replacements or repairs - including vehicle a/c failures. Out here if your a/c or power goes out during summer your house becomes unbearable in merely 3 hours or so.

A/C isn't an option in Arizona unless one wants to damage one's health. The rest of the world needs to be as prepared and have as much spare power as Arizona does. I'd like to see two new nuclear power plants 200 miles offshore of California with cabling to bring in the power. Perhaps another reactor inland somewhere to boot. CA imports a lot of juice from Arizona, which makes sure we have juice to spare. According to this chart CA hasn't produced enough electricity for its needs since at least 1983.