Count me in with a vote against the dual pane (PAIN) window! After 25 years of full-timing in 13 different rigs some with and some without dual panes, I would rather use extra heat/cooling than deal with the problems that come with dual pane windows. Our current MH, a ‘99 Bounder, has had almost every window removed and repaired over the years and even the repaired ones are in need of attention again. At $200 to $400 each for repair, that money would go a long way paying for extra propane or kilowatts! No other benefits from my experience!