Consider a brick house that is maintained at 20°C and 60 percent relative humidity at a location where the atmospheric pressure is 85 kPa. The walls of the house are made of 20-cm-thick brick whose permeance is 23 × 10?12 kg/s•m2•Pa. Taking the vapor pressure at the outer side of the wallboard to be zero, determine the maximum amount of water vapor that will diffuse through a 3-m × 5-m section of a wall during a 24-h period.
What will be an ideal response?What will be an ideal response?
The walls of a house are made of 20-cm thick bricks. The maximum amount of water vapor that will diffuse through a 3 m ? 5 m section of the wall in 24-h is to be determined.
Assumptions 1 Steady operating conditions exist. 2 Mass transfer through the wall is one-dimensional. 3 The vapor permeability of the wall is constant. 4 The vapor pressure at the outer side of the wall is zero.
Properties The permeance of the brick wall is given to be 23?10-12 kg/s.m2.Pa. The saturation pressure of water at 20ºC is 2339 Pa (Table 14-9).
Analysis The mass flow rate of water vapor through a plain layer of thickness L and normal area A is given by (Eq. 14-31)
You might also like to view...
A 5 ribbed serpentine belt should be tensioned at about ________.
A) 45 to 60 lbs. B) 150 lbs. C) 75 to 100 lbs. D) None of these
According to legend, who were the first people to use artificial insemination?
A) the Greeks B) the Russians C) the Chinese D) the Arabs
If an alternator has an "I" terminal it will be used to:
a. send power to the ignition circuit b. indicate to the ECM how much current the alternator is producing c. turn on the voltage regulator and excite the alternator d. turn on the rotor directly
Explain collusion and how it pertains to construction bids
What will be an ideal response?