Effect of windows in high R-value garage doors
New garage doors will list the R-value of a section with many having a value of 10 or higher. This value does not measure the total R-value of the door but only the section. If a single pane garage window is added, then the R-value of the window section many be 1 or lower. These are not published figures on the vendors web sites or in their brochures (at least I could not find them). Where do you get information on a single pane versus a double pane garage window, and how really deleterious to the total R-value of a garage door are the windows? The obvious answer of not getting windows may not be an option where esthetics, convenience, and additional light is an issue.