Which insulation material has an R-value of 3.44 per inch in the standard cited?

Which insulation material has an R-value of 3.44 per inch in the standard cited?

• A. Fiberglass
• B. Cellular-glass board insulation
• C. Mineral wool
• D. Polystyrene

Answer: (B)

R-value per inch shows how much insulating resistance a material provides for each inch of thickness. In the standard cited, cellular-glass board insulation is assigned an R-value of 3.44 per inch, which is higher than the typical per-inch values for fiberglass and mineral wool. This higher resistance comes from its closed-cell glass structure, which minimizes heat transfer more effectively per inch than the other materials listed. Polystyrene can vary by type, but the standard in this question does not align it with 3.44 per inch, making cellular-glass board insulation the match for the given value.

R-value per inch shows how much insulating resistance a material provides for each inch of thickness. In the standard cited, cellular-glass board insulation is assigned an R-value of 3.44 per inch, which is higher than the typical per-inch values for fiberglass and mineral wool. This higher resistance comes from its closed-cell glass structure, which minimizes heat transfer more effectively per inch than the other materials listed. Polystyrene can vary by type, but the standard in this question does not align it with 3.44 per inch, making cellular-glass board insulation the match for the given value.