Consider a 0 8 m high and 1 5 m wide double pane window consisting of two 4 mm thick layers of glass k 0 78 W mK separated by a 10 mmwide stagnant air space k 0 026 W mK Determine the steady rate of eat transfer through this double pane window and the temperature of its inner surface for a day during which the room is maintained at 20 C while the temperature of the outdoors is 10 C Take the convection heat transfer coefficients on the inner and outer surfaces of the window to be h1 10 W m2 C and h2 40 W m C which includes the effects of radiation 69 2 W 14 2 C