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ME 300 HW6 Due Date: 10/05/2015

Please submit in person during class. Please ensure that your write your last

name and first name in Block letters on the Homework.

(G15). A closed, rigid container with a volume of 1.2 m3contains moist air initially at 140

oC,

0.35 MPa, and 60% relative humidity. The moist air is cooled to the final temperature of 40oC.

Determine the mass of dry air, water vapor, and liquid water (if applicable) at the final state in kg,

and the heat transfer in kJ.

(G16). An air conditioning system supplying all outdoor air is installed in a building. The

outdoor air directly goes through the cooling coil and is cooled and dehumidified. The finaltemperature of the cooled air is 14

oC. The pressure is a constant at 101.3 kPa. It is found that the

mass flow rate of condensed water is 0.8 g/s when the outdoor temperature is 30oC and the

outdoor relative humidity is 80%. Determine the mass flow rate of the total outdoor air going

through the cooling coil in kg/s, and the heat transfer rate in W using the psychometric chart.

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(G17). A heating coil followed by steam humidifier is used in a building to supply warm air in

winter. The outdoor air is at a temperature of 5oC and relative humidity of 20%. The pressure is

a constant at 101.3 kPa. The measured heat transfer rate from the heating coil to the air is 3.5 kW.

The humidifier supplies steam to the air with a mass flow rate of 2 g/s. The steam is at a

temperature of 80oC. Determine the temperature, relative humidity of the air before and after the

humidifier, when the dry air mass flow rate is 0.2 kg/s.