Exercise 7 3-34 The wall of a refrigerator is constructed of fiberglass insulation (k=0.035 W/m K) sandwiched between two layers of 1-mm-thick sheet metal (k = 15.1 W/m-K). The refrigerated space is maintained at 2°C, and the average heat transfer coef- ficients at the inner and outer surfaces of the wall are 4 W/m²-K and 9 W/m²K, respectively. The kitchen temperature aver- ages 24°C. It is observed that condensation occurs on the outer surfaces of the refrigerator when the temperature of the outer surface drops to 20°C. Determine the minimum thickness of fiberglass insulation that needs to be used in the wall order to avoid condensation on the outer surfaces. Kitchen air 24°C 1 mm Sheet metal Insulation Refrigerated space 2°C mm

Exercise 7 3-34 The wall of a refrigerator is constructed of fiberglass insulation (k=0.035 W/m K) sandwiched between two layers of 1-mm-thick sheet metal (k = 15.1 W/m-K). The refrigerated space is maintained at 2°C, and the average heat transfer coef- ficients at the inner and outer surfaces of the wall are 4 W/m²-K and 9 W/m²K, respectively. The kitchen temperature aver- ages 24°C. It is observed that condensation occurs on the outer surfaces of the refrigerator when the temperature of the outer surface drops to 20°C. Determine the minimum thickness of fiberglass insulation that needs to be used in the wall order to avoid condensation on the outer surfaces. Kitchen air 24°C 1 mm Sheet metal Insulation Refrigerated space 2°C mm

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.

Chapter9: Heat Transfer With Phase Change

Section: Chapter Questions

Problem 9.37P

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