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 24ºC throughout the year, while the walls of the room are nominally at 26°C and 16°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.

Answer 1

Hello your question is incomplete below is the missing part of your question

Determine Heat flux due to convection

answer : 16 w/m^2

Step-by-step explanation:

Room temperature = 24°c

Room temperature during summer = 26°c

Room temperature during winter = 16°c

surface temp of person = 32°C

emissivity = 0.90

coefficient ( h ) = 2 W/m2.K

Determine Heat flux due to convection

Q" = h ( Δ T ) = coefficient * ( surface temp of person - room temperature )

= 2 * ( 32 - 24 ) = 16 w/m^2