I say put it where you think it will do the best job.
But one thing to be carful about, depending on your sinuses. Outside humidity low and inside will be high. Right now Tucson is 28%. If you crank up humidity inside RV high, some people get nose bleeds or headaches from the humidity changes. No big deal for most people. I'm not a Dr or anything even close to one. Only reason I know is because last year of a couple next to us. They are from a high humidity area and she kept getting nose bleeds while in Yuma, where low humidity is the norm. She eventually went to a Dr and now keeps RV in the 40-50 range. Probably lots on-line about what is best ranges.