(Solved): On a cold winter day, the inside of a window of a heated building is colder than the inside surroun ...

On a cold winter day, the inside of a window of a heated building is colder than the inside surrounding air. Natural convection results from this temperature difference. (a) Imagine this window as a vertical surface where $T_s<T_{\infty }$, sketch the resulting boundary layer that forms. Also sketch the velocity profile of the air through the boundary layer. (b) What are the key differences between the velocities in this boundary layer and those caused by forced convection? (c) If the window is $1.5\mathrm{m}$ tall and $1.0\mathrm{m}$ wide and has a temperature of $T_{\gamma }-0^{\circ }\mathrm{C}$, estimate the heat loss through the window if the room temperature is $T_{z\alpha }=T_{\alpha }=20^{\circ }\mathrm{C}$. Assume the emissivity of the glass surface is 0.95 .