Never mind the techno mumbo jumbo. If poor installation prevents the 13,500 BTU from being extracted it is all meaningless.
For example I am certain a good portion of my cold air leaks into the ceiling cavity. Otherwise why would cold air come out of the electric outlets?
Secondly my plenum divider was poorly installed causing the cold air to just recirculate within the air unit. Some duct tape fixed this.
On top of that my freeze sensor was not placed properly on the evaporator to cycle the compressor during high humidity cooling. Does not cool very well if no air gets through the block of ice on the evaporator.
I always read posts about these larger trailers with just 13.5K BTU cooling fine in 95+ heat... to you lucky ones, don't ever sell that RV. You will regret it.
Some day I may rip the ceiling down and fix it right. Mine does cool off after the sun goes down but not much immediate relief after a long hot drive through the desert.