Air is heated and humidified in air conditioning process. Mist humidifier is used. The mass flow rate of inlet air is 20 kg/s, temperature -5 °C and relative humidity 40%. After heating, the temperature of air is 30 °C. After mist humidifier, the relative humidity of air is 70%. Calculate or look up from Mollier chart: 1) Enthalpy of inlet air 2) Absolute humidity of inlet air 3) Enthalpy of heated air 4) Relative humidity of heated air 5) Absolute humidity of heated air 6) Heating power kJ/kg (with one decimal accuracy) g/kgdry air (with one decimal accuracy) kJ/kg (with one decimal accuracy) % (with zero decimal accuracy) g/kgdry air (with one decimal accuracy) kW (with zero decimal accuracy) 7) Absolute humidity after humidifier 8) Mass flow rate of the humidifier mist 9) Temperature after humidifier 10) Enthalpy after humidifier g/kgdry air (with one decimal accuracy) kg/s (with three decimal accuracy) °C (with one decimal accuracy) kJ/kg (with one decimal accuracy)

D. Much of the humidity in the air comes from vaporization from large bodies of water, like the Schuylkill and Delaware Rivers. Assuming the area of Philadelphia is 3.6 x 108 m² and the height of the city is 297 m (top of Comcast center), calculate the energy needed to reach 100% humidity by vaporizing water from the rivers at the afternoon high temperature. (For the sake of this exercise, assume ideal gas applies) a. Having trouble? Review questions from Chapter 10: 51.

During performances, a theatre experiences a sensible heat load of 500,000 Btu/hr and moisture load of 175 Ib/hr. Air enters the theatre at 65°F and 55% relative humidity and is removed when it reaches 75°F or 60% relative humidity, whichever comes first. What is the ventilation rate in mass of air per hour?

An apartment has the dimensions 12 m by 6 m by 4 m. The temperature is 30°C, and the relative humidity is 56 percent. What is the total mass (in kg) of water vapor in the air in the apartment? _______ kg

Dry air inlet temperature 23.9 (t1) Wet air inlet temperature 20.5 (t2) Dry air outlet temperature 24.3 (13) Wet air outlet temperature 23.1 (14) Inlet (A) Outlet (B) Set 2 Set 1 T [°C] Inlet (A) Outlet (B) (b) By using the psychrometric chart, fill up the table below for mass balance. Set 1 v[m/kg dry w[kg/kg dry air] Inlet (A) Outlet (B) 0.0183 0.017 [kg/kg dry air] 61 Set 2 T [°C] 68 24.2 20.8 25.4 24.5 aur] 0.86 v[m³/kg dry air m (c) By using the psychrometric chart, fill up the table below for energy balance. het [kJ/kg dry air] het [kJ/kg dry air [kg dry air/s] 0.0586 m [kg dry air/s] 6

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