The room shown in Fig. P13-39E is 20 ft by 20 ft wide and 9 ft high. The floor is at 100°F...

The room shown in Fig. P13-39E is 20 ft by 20 ft wide and 9 ft high. The floor is at 100°F, the walls are at 60°F, and the ceiling is at 40°F. All surfaces are assumed black. Calculate the net radiation heat transfer (a) from floor to walls and (b) from floor to ceiling.

FIGURE P13–39E