$17-19.$ Consider a $1\mathrm{.}2$ m high and $2$ m wide double pane window consisting of two $17$ mm thick layers of glass $(k=0\mathrm{.}78\frac{W}{m}.C)$ separated by a $12$ mm wide stagnant air space $(k=0\mathrm{.}026\frac{W}{m}.C).$ Determine the steady rate of heat transfer through this double pane window and the temperature of its inner surface for a day during which the room is maintained at $24C$ while the temperature of the outdoors is $-5C.$ Take the convection heat transfer coefficients on the inner and outer surfaces of the window to be $h1=10\frac{W}{m^2}.C$ and $h2=25\frac{W}{m^2}.C,$ and disregard any heat transfer by radiation. $($Answer: $114W,19\mathrm{.}2C)$