Which insulation material has an R-value of R7.2?

Polyisocyanurate foam is known for its high thermal resistance, which is measured by its R-value. The R-value indicates the effectiveness of insulation in resisting heat flow; the higher the R-value, the better the material insulates. Polyisocyanurate foam typically has an R-value in the range of R6 to R8 per inch of thickness, making it an excellent insulation choice for a variety of applications. An R-value of R7.2 is characteristic of polyisocyanurate foam, affirming its capabilities in providing superior thermal insulation in buildings.

In contrast, polyurethane expanded foam generally falls in a similar range as polyisocyanurate, but its specific formulations may yield different R-values. Cellulose, an organic material derived from recycled paper, tends to have lower R-values, usually around R3.5 to R4 per inch. Cellular glass insulation is also effective but generally has an R-value lower than that of polyisocyanurate, often around R3.2 to R4.0. Thus, polyisocyanurate foam stands out as the correct answer specifying an R-value of R7.2.