[southernnorthcarolina]

I've long felt that air conditioning was one of the most underrated innovations in terms of effects on settlement patterns, economic development, and even the political lay of the land. Where would the "Red States" (most of them in warm-weather states) be without air conditioning?

It is possible, with deep overhangs, shade trees, screens, attention to orientation with regard to the Sun, fans, and cross ventilation, to have a somewhat habitable single family house even in desert climes. But a factory or a large office building? The problems are almost insurmountable. I have an interest in a medium-sized office building in Charlotte. Air conditioning is required for some parts of the interior even when the outside temperature is in the 40s. How hot would a crowded elevator in an un-air conditioned office building on a 105º day in Tucson be?

[RayChuang88]

I think what the success of air conditioning did was to make high-temperature areas of the world habitable on a very large scale. That innovation made it possible to build cities in the arid US Southwest and the very hot and humid US Southeast.