Chapter 4, Problem 4.26P

A cubical glass melting furnace has exterior dimensionsof width $W=5\text{m}$ on a side and is constructed fromrefractory brick of thickness $L=0.35\text{m}$ and thermalconductivity $k=1.4\text{W/m}\cdot \text{K}\text{.}$ The sides and top of thefurnace are exposed to ambient air at $\text{25°C,}$ with freeconvection characterized by an average coefficient of $h=5{\text{W/m}}^2\cdot \text{K}\text{.}$ The bottom of the furnace rests on aframed platform for which much of the surface isexposed to the ambient air, and a convection coefficientof $h=5{\text{W/m}}^2\cdot \text{K}$ may be assumed as a first approximation.Under operating conditions for which combustiongases maintain the inner surfaces of the furnace at $1100°\text{C,}$ what is the heat loss from the furnace?