A furnace wall has 2 layers of brick. The first layer is 4.5" thick and has a thermal conductivity of .08 Btu/HR-ft-F. The second layer is 9" of a different type of brick with a thermal conductivity of .5 Btu/HR- ft-F. The inner and outer temperature of the surfaces are 1200 F and 180 F respectively. What is the rate of heat being loss through the wall? Assume the area of the wall is 1 square foot. Brick Brick Brick 4.59