Chapter 1, Problem 61P

A concreate wall a surface area of 20 m² and a thickness of 0.30 m separates conditioned room air from ambient air. The temperature of the inner surface of the wall (T₁) is maintained at ${25}^{\circ }\text{C}\text{.}$

(a) Determine the heat loss $Q(W)$ through the concrete wall for three thermal conductivity values of 0.75, 1, and 1.25 W/m⋅K and outer wall surface temperatures of $T2=-15,-10,-5,0,0,5,10,15,20,25,30,$ and ${38}^{\circ }\text{C}$

(a total of 11 data points for each thermal conductivity value). Tabulate the result for all three cases in one table. Also provide a computer-generated graph [Heat loss, $Q(W)$ vs. Outside wall temperature, $T_2{(}^{\circ }C)]$ for the display of your results. The results for all three cases should be plotted on the same graph. (b) Discuss your results for the three cases.