$7\mathrm{.}27$ Figure P$\mathrm{.}27$ provides steady$-$state data for the outer wall of a dwelling on a day when the indoor temperature is maintained at $25C$ and the outdoor temperature is $35C.$ The heat transfer rate through the wall is $1000$ W $.$ Determine, in W $,$ the rate of exergy destruction $($a$)$ within the wall, and $($b$)$ within the enlarged system shown on the figure by the dashed line. Comment. Let $T_O=35C.$

FIGURE P$7.27$