Ac's in homes are quiet because the handler is usually someplace out of the living space and insulated. The ducting massive and is also behind walls and insulated and a house has a lot of floorspace and walls to deflect and absorb sound. Your AC in your RV is literally on top of your head with very little insulation and no real ductwork and your RV interior is about the size of standard home kitchen with an open floorplan with no walls to deflect noise. They move a lot of air to try to cool a space with very little R value. And they are cheap and less efficient. Our last FW had a true ducted system and was actually pretty quiet. The AC on our new MH is a GE (never knew they made RV AC's) and it's not the loudest I've had. When I'm outside - even at a quiet SP I can hardly hear it.