Question

A composite wall 8.5 ft X 10.5 ft is made of 1.5-in.-thick gypsum plaster and 1.62-in.- thick fir. When a temperature difference of 85°F exists across the wall, what thickness of mineral wool insulation must be added to limit heat transfer through the wall to 820 Btu/hr? What is the thermal resistance of the wall?

Answer 1