14.5 Exercise 8

(a) Calculate the rate of heat conduction through house walls that are 13.0 cm thick and that have an average thermal conductivity twice that of glass wool. Assume there are no windows or doors. The surface area of the walls is $\text{120} \text{m}^{2}$ and their inside surface is at $\text{18}. 0º \text{C}$, while their outside surface is at $5 .\text{00}º \text{C}$. (b) How many 1-kW room heaters would be needed to balance the heat transfer due to conduction?