Overview
This is where camper comfort becomes an electrical-design problem.
A roof AC can make summer travel possible in places where fans and shade are not enough. In Phoenix-adjacent heat, that is not a small difference.
But it is not just an appliance. It affects roof structure, sealing, shore power, generator choice, inverter sizing, battery capacity, and where you can realistically camp.
This belongs in a serious trailer or van build where comfort is worth the install and the electrical system is designed around the load.
AC is comfort, but the power system decides whether it is usable.