Consider a brick house (k = 0.72 W/m · °C and α = 0.45 × 10-6 m2/s) whose walls are 10 m l...

Consider a brick house (k = 0.72 W/m · °C and α = 0.45 × 10-6 m2/s) whose walls are 10 m long, 3 m high, and 0.3 m thick. The heater of the house broke down one night, and the entire house, including its walls, was observed to be 5°C throughout in the morning. The outdoors warmed up as the day progressed, but no change was felt in the house, which was tightly sealed. Assuming the outer surface temperature of the house to remain constant at 15°C, determine how long it would take for the temperature of the inner surfaces of the walls to rise to 5.1°C.

FIGURE P18-110