A wall is constructed of two layers of 0.7-in-thick sheetrock (k = 0.10 Btu/h·ft·°F), which is a

Question:

A wall is constructed of two layers of 0.7-in-thick sheetrock (k = 0.10 Btu/h·ft·°F), which is a plasterboard made of two layers of heavy paper separated by a layer of gypsum, placed 7 in apart. The space between the sheetrocks is filled with fiberglass insulation (k = 0.020 Btu/h·ft·°F). Determine

(a) The thermal resistance of the wall

(b) Its R-value of insulation in English units.

Fiberglass Insulation Sheetrock 0.7 In - 7 in- 0.7 In