A glass window of width W=1 m and height H=2 m is 5 mm thick and has a thermal conductivity of kg=1.4 W/m-K. If the inner and outer surface temperatures of the glass are 15°C and -20°C, respectively, on a cold winter day, what is the rate of heat loss through the glass? To reduce heat loss through windows, it is customary to use a double pane construction in which adjoining panes are separated by a dead-air space.