Solve the folloiwng problem:
Q: Heat is transferred through a plane wall from the inside of a room at 22°C to the outside air at -2°C. The convective heat transfer coefficients at the inside and outside surfaces are 12 and 28 W/(m2 K), respectively. The thermal resistance of a unit area of the wall is 0.5 m2 K/W. Determining the temperature at the outer surface of the wall and the rate of heat flow through the wall per unit area.
GIVEN
Heat transfer through a plane wall
Air temperature
Inside wall (Ti) = 22°C and outside wall (To) = -2°C
Heat transfer coefficient
Inside wall ( hci ) = 12 W/(m2 K)
Outside wall ( hco ) = 28 W/(m2 K)
Thermal resistance of a unit area (A Rw) = 0.5 (m2 K)/W
ASSUMPTIONS
One dimensional heat flow
Steady state has beenreached
