We had a portable AC in the campground wood log office that I worked in last summer. The office sat in the sun with asphalt drive all around it. When it was 90+ outside, the portable AC did cool the office from say 98 down to maybe 89, but it was hot and miserable all summer even with that running all the time. It was the biggest btu you can get without needing a 220 plug in. The office was small with a small porch and windows . It did not work well in extreme hot, sunny, weather. If you sit in the desert with no shade and in the sun all day, I wouldn't count on it helping much.