Chapter 9 Natural Convection9-87 The U-factor for the center-of-glass section of a double pane window is to be determined. Assumptions1 Steady operating conditions exist. 2Heat transfer through the window is one-dimensional. 3 The thermal resistance of glass sheets is negligible. PropertiesThe emissivity of clear glass is given to be 0.84. The values of hiand hofor winter design conditions are hi= 8.29 W/m2.°C and ho= 34.0 W/m2.°C (from the text). AnalysisDisregarding the thermal resistance of glass sheets, which are small, Air space ih1space1hoh1ε= 0.84 Glass 13 mm the U-factor for the center region of a double pane window is determined from 111Uhhiocenterspace≅++1hwhere hi, hspace, and hoare the heat transfer coefficients at the inner surface
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This note was uploaded on 01/24/2012 for the course PHY 4803 taught by Professor Dr.danielarenas during the Fall '10 term at UNF.