Just curious what harm can come from not turning on the AC. Lots of RV's (mine included) are in storage or on dealer lots where there is no electric. It gets hot here in the summer. Today is close to 100 with heat indexes as high as 112. I've never had an issue as a result and don't recall reading complaints about issues from not running the AC. I keep the blinds closed when in storage mainly to prevent any fading on interior surfaces. Unless I am missing something, running the AC is a solution looking for a problem. Maybe I am missing something - although if I am, it's a moot point for me as I don't keep my RV at my house.