advice on air conditioners in hot weather

[encantotom]

hi, i am looking to buy a late 80's newell 40 foot coach and i live in the phoenix area. do coaches with 3 basement airs of 13.5kbtu's work well enough to cool at 100-110 degree's? i want to be able to use it in the summer and don't want to die of heat stroke. have any of you with the 3 basement airs had experience in very hot weather with them and can give some advice on how well they work? are there late 80's that have roof airs and if so how do they work with in the hot summer weather? thanks for your advice!