This is a topic we can spend much time discussing. In my opinion...
Window condensation is a symptom of a homes level of humidity that typically shows up at the bottom of the glass on a window. As higher humidity during the winter months is a feel-good condition, too much inside humidity during extreme cold, outside temps causes the condensation of moisture showing up on the windows having an effect on the finish and unsightly darkening of wood components no matter the brand.
I have available literature from various manufactures and 3rd party explaining this, to help you understand and help manage it. There are various graphs available explaining the recommended level of inside humidity in correlation to the outside temps during winter to help manage the damaging effects of window condensation. In my opinion as the outside temp lowers so should the inside humidity follow it, other conditions and living practices i.e. screens, blinds, shades window coverings, pets, plants and cooking all contribute to excessive window condensation. With installing new sashes or new window components with new weather stripping can actually increase an obvious condition of high humidity condensation and the windows typically take the blame, but it’s not the windows fault as the literature explains this.
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