Yasmine Estes

Physics

1 November, 11:21

A house is maintained at 1 atm and 24°C. Outdoor air at 5.5°C infiltrates into the house through the cracks and warm air inside the house is forced to leave the house at a rate of 90 m3 / hr. The gas constant of air is R = 0.287 kPa·m3 / kg·K. The constant pressure specific heat of air at room temperature is cp = 1.005 kJ/kg:°C.

a. Create a schematic representation of the system, indicating all the mass and energy interactions across the boundary.

b. Determine the mass flow rate of the warm air exiting the house (in kg/s).

c. Determine the mass flow rate of the cold air entering the house (in kg/s).

d. Determine the rate of net energy loss of the house due to mass transfer (in kW).

e. List the assumptions and approximations that were needed to solve this problem.