I just had an Anderson 400 double hung,side-by-side window installed by a reputable contractor. Since the installation on each cold morning I have iced condensation or just condesation on the outside of the windows. It's definitely on the outside as I went out to scrape the ice to double check. The window faces north, and a river and marsh.Is this something wrong or is the window or is it simply that the window is good, and that the combination of morning dew and cold is creating this situation. No other window in the house is doing this. I am concerned if I cold call the window company and ask the question, they will they give me a straight answer?