A cubical glass melting furnace has exterior dimensions of width W = 5 m on a side and is constructed from refractory brick of thickness L = 0.35 m and thermal conductivity k = 1.4 W/m. K. The sides and top of the furnace are exposed to ambient air at 25°C, with free convection characterized by an average coefficient of h = 5 W/m2 ∙ K. The bottom of the furnace rests on a framed platform for which much of the surface is exposed to the ambient air and a convection coefficient of h = 5 W/m2 ∙ K may be assumed as a first approximation. Under operating conditions for which combustion gases maintain the inner surfaces of the furnace at 1 100°C, what is the heat loss from the furnace?