I traded in a Glendale Titanium for a brand new Bighorn...New unit has 2 15000 AC whisper units and doesn't cool as well as I would have thought..But that isn't the issue..When I sit on the couch all I feel is the vibration of the unit...If the unit is off, there is no vibration....Had the Glendale for 13 years with single AC unit, same size at 40 feet...Never felt the vibration like I feeling with The Bighorn. I am assuming this in not normal, can anyone shed any light on this?? I can actually watch a glass filled with water on the counter have ripples.