Chapter 3 Steady Heat Conduction3-19A double-pane window consists of two 3-mm thick layers of glass separated by a 12-mm wide stagnant air space. For specified indoors and outdoors temperatures, the rate of heat loss through the window and the inner surface temperature of the window are to be determined. Assumptions1Heat transfer through the window is steady since the indoor and outdoor temperatures remain constant at the specified values. 2 Heat transfer is one-dimensional since any significant temperature gradients will exist in the direction from the indoors to the outdoors. 3 Thermal conductivities of the glass and air are constant. 4 Heat transfer by radiation is negligible. PropertiesThe thermal conductivity of the glass and air are given to be kglass= 0.78 W/m⋅°C and kair= 0.026 W/m⋅°C. Analysis The area of the window and the individual resistances are A=×=(.(.12224
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