The roof of a house consists of a 0.70-ft-thick concrete slab (k = 3 W/m · °C) that is 18 m wide and 23 m long. The emissivity of the outer surface of the roof is 0.92, and the convection heat transfer coefficient on that surface is estimated to be 18 W/m² · °C. The inner surface of the roof is maintained at 295 K. On a clear winter night, the ambient air is reported to be at 282.15 K while the night sky temperature for radiation heat transfer is 260 K. Considering both radiation and convection heat transfer, determine the outer surface temperature and the rate of heat transfer through the roof.

The roof of a house consists of a 0.70-ft-thick concrete slab (k = 3 W/m · °C) that is 18 m wide and 23 m long. The emissivity of the outer surface of the roof is 0.92, and the convection heat transfer coefficient on that surface is estimated to be 18 W/m² · °C. The inner surface of the roof is maintained at 295 K. On a clear winter night, the ambient air is reported to be at 282.15 K while the night sky temperature for radiation heat transfer is 260 K. Considering both radiation and convection heat transfer, determine the outer surface temperature and the rate of heat transfer through the roof.

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.

Chapter1: Basic Modes Of Heat Transfer

Section: Chapter Questions

Problem 1.7P: A cooling system is to be designed for a food storage warehouse for keeping perishable foods cool...

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