A wall constructed of three layers is to be considered. The inner surface of the wall is maintained at 23 C and the outer surface is 8 C. The combined convection and radiation heat transfer coefficients are 17 W/m^2*K. The inner layer is plaster with 1cm thickness and k=0.36 W/m*K. The middle layer is brick 20 cm thickness and k=0.72 W/m*K and the outer layer is cement 2 cm thickness and k=1.4 W/m*k. The wall system is 6m wide by 2.8m high.
What is the rate of heat transfer through the wall and temperature drops accross each layer, and surface-ambient air?