Air flowing through a direct-expansion cooling coil at the rate of 3.2 kgsí1 enters with a db–temperature of 31°C and a wb–temperature of 21°C. At the exit the air is at 13°C db-temperature and 90%...

Air flowing through a direct-expansion cooling coil at the rate of 3.2 kgsí1 enters with a db–temperature of 31°C and a wb–temperature of 21°C. At the exit the air is at 13°C db-temperature and 90% relative humidity. The temperature of the refrigerant is 12°C. The outside and inside heat transfer coefficients are 0.065 kWmí2 Kí1 and 2.6 kWmí2 Kí1 respectively. The ratio of the outside to inside heat transfer areas is 15. Calculate (i) the area of the dry section of the coil, (ii) the total area of the coil, (iii) the total cooling capacity, and (iv) the temperature and humidity ratio of the air at the exit. Plot the condition line of the air on the psychrometric chart