Problem 84P

Energy Analysis of Control Volumes at Steady State

Figure P4.84 provides steady-state data for the ducting ahead of the chiller coils in an air conditioning system. Outside air at 90°F is mixed with return air at 75°F. Stray heat transfer is negligible, kinetic and potential energy effects can be ignored, and the pressure throughout is 1 atm. Modeling the air as an ideal gas with cp = 0.24 Btu/lb · R, determine (a) the mixed-air temperature, in °F, and (b) the diameter of the mixed-air duct, in ft.

Solution 84P

Step 1 of 5:

In this question, we need to find temperature of mixed air in

In part b, we need to find the diameter of the mixed air duct in

Data given

Temperature of outside air

Temperature of mixed air

Pressure

Specific pressure

Part a: