A concrete wall with 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°C.

(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 = 215, 210, 25, 0, 5, 10, 15, 20, 25, 30, and 38°C (a total of 11 data points for each thermal conductivity value). Tabulate the results for all three cases in one table. Also provide a computer-generated graph [Heat loss, Q (W) vs. Outside wall temperature, T₂ (°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.