Why are there different R-Values or insulation properties of garage doors?
Many manufacturers use R-values to show the energy efficiency of their product. This number is arrived at through a calculation that looks at the thickness of the insulation and its chemical properties. Therefore, most of the R-value numbers you see, reflect only the R-value of the section…not of the installed door. A door’s insulating capabilities can be greatly affected by the door’s construction. Polyurethane is a much better and more efficient insulator than polystyrene.
