Under conditions for which the same room temperature is maintained by a heating or cooling system, it is not uncommon for a person to feel chilled in the winter but comfortable in the summer. Consider a room whose air temperature is maintained at 22°C throughout the year, while the walls of the room are nominally at 24°C and 12°C in the summer and winter, respectively. The exposed surface of a person in the room may be assumed to be at a temperature of 32°C throughout the year and to have an emissivity of 0.90. The coefficient associated with heat transfer by natural convection between the person and the room air is approximately 2 W/m2-K. Calculate the following. Heat flux due to convection: qCony = i W/m? Heat flux due to radiation in the summer: Tad W/m2 i Heat flux due to radiation in the winter: Trad W/m2 %3D

Under conditions for which the same room temperature is maintained by a heating or cooling system, it is not uncommon for a person to feel chilled in the winter but comfortable in the summer. Consider a room whose air temperature is maintained at 22°C throughout the year, while the walls of the room are nominally at 24°C and 12°C in the summer and winter, respectively. The exposed surface of a person in the room may be assumed to be at a temperature of 32°C throughout the year and to have an emissivity of 0.90. The coefficient associated with heat transfer by natural convection between the person and the room air is approximately 2 W/m2-K. Calculate the following. Heat flux due to convection: qCony = i W/m? Heat flux due to radiation in the summer: Tad W/m2 i Heat flux due to radiation in the winter: Trad W/m2 %3D

Elements Of Electromagnetics

7th Edition

ISBN:9780190698614

Author:Sadiku, Matthew N. O.

Publisher:Sadiku, Matthew N. O.

ChapterMA: Math Assessment

Section: Chapter Questions

Problem 1.1MA

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Question

Under conditions for which the same room temperature is maintained by a heating or cooling system, it is not uncommon for a person
to feel chilled in the winter but comfortable in the summer.
Consider a room whose air temperature is maintained at 22°C throughout the year, while the walls of the room are nominally at 24°C
and 12°C in the summer and winter, respectively. The exposed surface of a person in the room may be assumed to be at a temperature
of 32°C throughout the year and to have an emissivity of 0.90. The coefficient associated with heat transfer by natural convection
between the person and the room air is approximately 2 W/m2-K.
Calculate the following.
Heat flux due to convection:
qbonv
W/m?
Heat flux due to radiation in the summer:
Trad
i
W/m?
Heat flux due to radiation in the winter:
gad
W/m?
i
Physical Properties Mathematical Functions

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