The room is 20 ft by 20 ft wide and 9 ft high. The floor is at 100°F, the walls are at 60°F, and the ceiling is at 40°F. All surfaces are assumed black. Calculate the net radiation heat transfer (a) from floor to walls and (b) from floor to ceiling.

The room is 20 ft by 20 ft wide and 9 ft high. The floor is at 100°F, the walls are at 60°F, and the ceiling is at 40°F. All surfaces are assumed black. Calculate the net radiation heat transfer (a) from floor to walls and (b) from floor to ceiling.

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 1.25P: 1.25 A spherical vessel, 0.3 m in diameter, is located in a large room whose walls are at 27°C (see...

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Concept explainers

Radiation

Radiation can be described as the energy in the form of a particular matter or electromagnetic waves traveling in the air and can be in the form of light, sound, and heat. Radiation can be detected through special instruments like X-rays. The radiation from a cooler object is less intense as compared to the radiation from hot objects.

Question

The room is 20 ft by 20 ft
wide and 9 ft high. The floor is at 100°F, the walls are at
60°F, and the ceiling is at 40°F. All surfaces are assumed
black. Calculate the net radiation heat transfer (a) from floor
to walls and (b) from floor to ceiling.

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1.25 A spherical vessel, 0.3 m in diameter, is located in a large room whose walls are at 27°C (see sketch). If the vessel is used to store liquid oxygen at –183°C and both the surface of the storage vessel and the walls of the room are black, calculate the rate of heat transfer by radiation to the liquid oxygen in watts and in Btu/h.