Consider a 0.6-m high and 2-m wide double-glazed window consisting of two 4 mm thick layers of glass (k = 0.80 W/m °C) separated by an 8-mm wide stagnant air space (k = 0.025 W/m °C). Determine the steady state heat transfer through the window and the temperature of the inner surface for a day when the outside air temperature is -15 °C and the room temperature is 20 °C. The heat transfer coefficient on the inner and outer surface of the window are 10 W/m2 °C and 40 W/m2 °C respectively. Note that these heat transfer coefficients include the effect of radiation. If the air gap is not provided, what is the temperature of the glass inside the room?