I suggest take a look at the ProVia Endure high grade vinyl window.
Triple pane is what I sell now and has very low U-factor and air infiltration.
I love their low profile slim casement window, just ... read more
Scott,
The easiest thing to do is check in the attic and look at the sheathing. If there is any mold growth, you can tread it with a proper mildewicide and make sure that the fan ducting is extended ... read more