A wall of a warehouse of dimensions 8 feet by 20 feet is made of concrete block of R-value 2 and an inside layer of foam insulation of R-value 10. When the outside temperature is 30°F and the inside temperature is 70°F.
a) Calculate the total heat flux through the wall.
b) Calcualate the temperature of the foam/concrete interface.
R-value has units of ft2°F h / BTU.