Air conditioning in new 5th Wheel

I own an old 5th wheel (2002 Cougar 27' long) and have one 15K BTU A/C. It is pretty new and replaced the original 13.5K btu unit. Some of the things we have done are to tint the windows so 90 percent of UVs are blocked. On our camper, the ends of the A/C runs just blew into the ceiling void so these are blocked with pool noodles. I also used aluminum heat duct tape to retape and the factory tape jobs as much of the air was not confined to the ducting system but ran into the void. In south Texas, temps of 93F require winter jackets and normal July temps are generally over 100F so we also have a 8K BTU portable A/C that I vent out through a side window and our cabin temps stay pretty comfortable. Don't use the portable A/C to augment the 15K unit in the winter. As noted, your dual A/Cs should keep your cabin nice and cool so look at how much heat your windows are letting in and check to see that ducting isn't loosing your cool air. I also had to redo the seal between the return side and outlet to the ducts up in the upper unit of my A/C as that was leaking cold air. I did this by taking off the lower part and doing it from underneath.