Hello I live in fort worth the summer time temp last year ranged from 80 at night to 100 daytime and the humidity always 50 to 90 percent.This was a mild summer.I have a 8 x35 5th wheel trailer,what i did was not use the rooftop a/c. They use 220 vac @10 amps and cost about $125to$150 a month to run.Instead i went to lowes and got a 120vac- 5000btu window a/c unit removed a window and put it in.The new small unit cools better and cost less to run, about 16.00 a month.The newer units are so much more eficent,you have to see it to belive it.