Problem 3 a. 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? b. To reduce heat loss through windows, it is customary to use a double pane construction in which adjoining panes are separated by an air space. If the spacing is 10 mm and the glass surfaces in contact with the air have temperatures of 10 C and -15 C, what is the rate of heat loss from a 1 m x 2 m window? The thermal conductivity of air is ka = 0.024 W/(m K). Hint... the air between the window panes can be treated as a stationary fluid. Approximate solutions: 20,000 W & 100 W