Answer to Question #210791 in Mechanical Engineering for SUJIT NAYAK

Question

A room (10 m× 5 m × 5 m)contains moist air at 38°C / 1 bar with relative humidity 70%. Determine the specific humidity?(where, Corresponding to the dry bulb temperature of 38° C, the saturation pressure of water vapour Ps=0.06624, From the Steam Table)

Answer 1

V = $10m × 5m × 5m$ = 250m³

density of air = 1.225 kg/m³

mass of air = 1.225kg/m³ × 250m³ = 306.25 kg

water = 83 g/m³

70% humidity = 70% × 83g/m³ = 0.0581kg/m³

mass of water = 0.0581 × 250 = 14.525kg

Specific Humidity = mass of water vapor per unit mass of air = 14.525/306.25 = 0.047