I'm trying to make a decision on whether to have an air conditioner installed on my van's roof. I plan to have solar power and an attic fan installed. I will be doing some boondocking. The guy at Sportsmobile said that the AC would run for only about one hour on the power stored in the batteries. I like my environment to be cool, and sometimes, I will be in Texas where the summers are blazing hot. Any advice would be appreciated.