Current Attempt in Progress

A dormitory at a large university, built $50$ years ago, has exterior walls constructed of $L_s=25-$mm$-$thick sheathing with a thermal

conductivity of $k_s=0\mathrm{.}1\frac{W}{m}*K.$ To reduce heat losses in the winter, the university decides to encapsulate the entire dormitory by

applying an $L_i=25-mm-$thick layer of extruded insulation characterized by $k_i=0\mathrm{.}029\frac{W}{m}*K$ to the exterior of the original

sheathing. The extruded insulation is$,$ in turn, covered with an $L_g=5-$mm$-$thick architectural glass with $k_g=1\mathrm{.}4\frac{W}{m}*K.$

Determine the heat flux through the original and retrofitted walls when the interior and exterior air temperatures are $T_{,i}=22C$

and $T_{,o}=-20C,$ respectively. The inner and outer convection heat transfer coefficients are $h_i=5\frac{W}{m^2}*K$ and $h_o=25\frac{W}{m^2}*K,$

respectively.

The heat flux through the original walls is

$\frac{W}{m^2}.$

The heat flux through the retrofitted walls is

$\frac{W}{m^2}$

Physical Properties Mathematical Functions