I don't think one could survive for long in SC with the heat and humidity with out air conditioning, and I live in one of the coolest spots in the state! About 30 minutes north of us, as you cross over into NC, most homes do not have air conditioning though, as they are in the mountains and the temps are much cooler there. My house is surrounded by trees, too. I have lived in homes that have window units before and those with central air. Although I prefer having open windows as much as possible, and like Rachel, always wonder about people who never open their windows, this time of year, there are no open windows, just A/C running. We run it in the car all the time, too. Even though we aren't as hot as we could be, with the humidity, we wouldn't be able to stand it.