Insulated windows may help, but this doesn't cure the problem. As we progress into the cooler months of fall and winter, the moisture that has penetrated your home during the summer usually dries out and less condensation is apparent. Overnight condensation, which builds up at night when temperatures drop outside, is normal. The outside temperatures cool the window glass and your windows will appear foggy or damp in the morning. When daylight returns, warming the temperature outside, condensation should dissipate.
Condensation is harmless if it dries up, but when it remains, it is a sign of trouble.
Persistent levels of moisture can damage your home structurally, resulting in dry rot, paint problems, and mold and mildew growth. If you have a continual problem with excess condensation on your windows, you are likely to have problems hidden in your walls and attic, too. Newer homes are much more prone to problems of this nature. With efforts to make homes more energy efficient, we have created interior environments that are too tight, without significant air leaks. There just isn't enough infiltrating air to flush out moisture.