glass each 4mm thick separated by a 23mm air gap. This window is a replacement for a single glazed unit. The double glazed unit is installed in the wall of a room in which the air temperature is maintained at 23 degreesC, the outer surface of the window is exposed to the atmospheric temperature which is 2 degreesC. The surface heat transfer coefficient of the room side glass is 5.7 W/m?K and 9.1 W/m?K on the outer surface of the window. The thermal conductivity of the glass is known to be 0.76 W/mK. i) On the assumption that the air gap between the layers may be regarded as a stationary layer of air of thermal conductivity 0.026 W/mK, calculate the heat transfer rate through the window and the temperature of the room side surface of the glass. ii) Calculate the heat transfer rate for the single glazed unit which has been replaced. The window was of the same dimensions consisting of a single pane of glass. It may be assumed that all of the remaining data are unchanged.

glass each 4mm thick separated by a 23mm air gap. This window is a replacement for a single glazed unit. The double glazed unit is installed in the wall of a room in which the air temperature is maintained at 23 degreesC, the outer surface of the window is exposed to the atmospheric temperature which is 2 degreesC. The surface heat transfer coefficient of the room side glass is 5.7 W/m?K and 9.1 W/m?K on the outer surface of the window. The thermal conductivity of the glass is known to be 0.76 W/mK. i) On the assumption that the air gap between the layers may be regarded as a stationary layer of air of thermal conductivity 0.026 W/mK, calculate the heat transfer rate through the window and the temperature of the room side surface of the glass. ii) Calculate the heat transfer rate for the single glazed unit which has been replaced. The window was of the same dimensions consisting of a single pane of glass. It may be assumed that all of the remaining data are unchanged.

Principles of Heat Transfer (Activate Learning with these NEW titles from Engineering!)

8th Edition

ISBN:9781305387102

Author:Kreith, Frank; Manglik, Raj M.

Publisher:Kreith, Frank; Manglik, Raj M.

Chapter4: Numerical Analysis Of Heat Conduction

Section: Chapter Questions

Problem 4.14P

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