Pat, I've got a small RV. 19 feet, with a small AC as well. Do you have a digital thermostat? If not install one. Generally what I do is keep all the windows and vents closed, as suggested to minimize power consumption. With the digital thermo I can set the temp just how I like it, and when the RV cools down to that level I may open a window for fresh air as long as it's not too hot outside. If it's 100 plus, like you are at, I'd keep all vents and windows closed up. Even with a small RV, I've never felt like I had bad air. Heck people drive for hours in the desert in small cars, with the AC on and no windows open, with no problems.