Chapter 1, Problem 1.3P

A concrete wall, which has a surface area of $\text{2}0{\text{ m}}^{\text{2}}$ andis 0.30 in thick, separates conditioned room air fromambient air. The temperature of the inner surface of thewall is maintained at 25°C, and the thermal conductivity of the concrete is $1\text{W/m}\cdot \text{K}$ .
(a) Determine the heat loss through the wall for outersurface temperatures ranging from $-\text{15}°\text{C}$ to 38°C,which correspond to winter and summer extremes,respectively. Display your results graphically.
(b) On your graph, also plot the heat loss as a function ofthe outer surface temperature for wall materials having thermal conductivities of 0.75 and $1.25\text{W/m}\cdot \text{K}$ . Explain the family of curves you have obtained.