On a hot summer day, the flat roof of a tall building reaches 50° C in temperature. The area of the roof is 400m2. Estimate the heat radiated from this roof to the sky in the evening when the temperature of the surrounding air or sky is at 20° C. The temperature of the roof decreases as it cools down. Estimate the rate of energy radiated from the roof, assuming roof temperatures of 50, 40, 30, and 25° C. Assume ε = 0 9 . for the roof.

On a hot summer day, the flat roof of a tall building reaches 50° C in temperature. The area of the roof is 400m2. Estimate the heat radiated from this roof to the sky in the evening when the temperature of the surrounding air or sky is at 20° C. The temperature of the roof decreases as it cools down. Estimate the rate of energy radiated from the roof, assuming roof temperatures of 50, 40, 30, and 25° C. Assume ε = 0 9 . for the roof.

Sustainable Energy

2nd Edition

ISBN:9781337551663

Author:DUNLAP, Richard A.

Publisher:DUNLAP, Richard A.

Chapter14: Ocean Thermal Energy Conversion And Ocean Salinity Gradient Energy

Section: Chapter Questions

Problem 19P

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