1. A flow of 2,000 CFM moist outdoor air at 90F and 70% RH mixes with a 1,000 CFM stream of return air at 65F and 20% RH. The properties of each stream are in the table below. The ambient pressure is 14.70 psi a. Calculate the mass flow rate of the mixed air stream (lbm/hr) b. Calculate the enthalpy (BTU/lbm) and humidity ratio of the mixed air stream. c. Calculate the relative humidity (RH) of the mixed air stream assuming the saturation pressure at the temperature of the mixed air stream is 0.52 psi. T RH Density h F % lbm/ft BTU/lbm lbm/lbm Ambient 90 70 0.06289 Return 65 20 0.07530 45.16 13.28 0.002598 0.02141