02. An electronic box that consumes 180 W of power is cooled by a fan blowing air into the box enclosure The dimensions of the electronic box are 15 cm x 50 cm x 50 cm, and all surfaces of the box are exposed to the ambient except the base surface. Temperature measurements indicate that the box is at an average temperature of 32°C when the ambient temperature and the temperature of the surrounding walls are 25°C. The emissivity of the outer surface is 0.85. Determine: (a) The heat lost from the top surface, (b) The heat lost from the side surfaces, (c) The total heat lost by radiation and (d) the total fraction of the heat lost from the outer surfaces of the electronic box.

02. An electronic box that consumes 180 W of power is cooled by a fan blowing air into the box enclosure The dimensions of the electronic box are 15 cm x 50 cm x 50 cm, and all surfaces of the box are exposed to the ambient except the base surface. Temperature measurements indicate that the box is at an average temperature of 32°C when the ambient temperature and the temperature of the surrounding walls are 25°C. The emissivity of the outer surface is 0.85. Determine: (a) The heat lost from the top surface, (b) The heat lost from the side surfaces, (c) The total heat lost by radiation and (d) the total fraction of the heat lost from the outer surfaces of the electronic box.

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.

Chapter3: Transient Heat Conduction

Section: Chapter Questions

Problem 3.11P

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