Just broke down and added the 2nd AC unit in bedroom on our 37" Jayco Designer. Trip to LA and AL with 90 degree temps convinced us. One of our major issues was the noise since the AC sits right ove...
We turn both on to cool down the trailer then just run 1... At night we always keep the 2nd one on , it's kind of like white noise to me ! Once the trailer is cooled you can run either as long as they both are ducted... Joe