Chapter 3, Problem 3.20P

The $t=4\text{-mm-thick}$ glass windows of an automobilehave a surface area of $A=2.6{\text{m}}^2.$ Theoutside temperatureis $T_{\infty ,o}=32°\text{C}$ while the passenger compartmentis maintained at $T_{\infty ,i}=22°\text{C}\text{.}$ The convection heattransfer coefficient on the exterior window surface is $h_o=90{\text{W/m}}^2\cdot \text{K}\text{.}$ Determine the heat gain through thewindows when the interior convection heat transfercoefficient is $h_i=15{\text{W/m}}^2\cdot \text{K}\text{.}$ By controlling the airflowin the passenger compartment the interior heattransfer coefficient can be reduced to $h_i=5{\text{W/m}}^2\cdot \text{K}$ without sacrificing passenger comfort. Determine theheat gain through the window for the reduced inside heattransfer coefficient.