An air conditioning system comprises a chiller, heater, mixing chamber and associated ductwork and fans. vlt...

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An air conditioning system comprises a chiller, heater, mixing chamber and associated ductwork and fans. vlt is used to maintain the environment in an exercise room at 22°C (dry bulb) and 50% percentage saturation when the outside conditions are 32°C (dry bulb) and 80% percentage saturation. Heat gains through the fabric of the building are estimated to be 3400 W. Gains from electrical equipment (including lighting) are 1.3 kW and when fully operational 20 people are exercising vigorously. The conditioned air entering the room comprises 20% fresh air and 80% recirculated air. The fan power and heat transfer to and from the ducts may be neglected. The evaporator of the chiller has an apparatus dew point of 8°C and a coil bypass factor of 10%. For an individual exercising vigorously the load may be taken as 210 W Sensible heat and 315 W latent heat. (a) Show each process and clearly label the state points on the psychometric chart provided. (7 marks) Calculate: (i) the airflow through the chiller. (ii) the rate of moisture removal in the chiller. (iii) the rate of heat removal in the evaporator of the chiller (iv) the rate of heat supplied in the heater. (2 marks) (2 marks) (2 marks) (2 marks) (b) If all other design parameters (including apparatus dewpoint) remain the same, estimate, with justification, the highest value of coil bypass factor at which the air conditioner could meet its specification. Explain why operating under these conditions is undesirable. (6 marks) An air conditioning system comprises a chiller, heater, mixing chamber and associated ductwork and fans. vlt is used to maintain the environment in an exercise room at 22°C (dry bulb) and 50% percentage saturation when the outside conditions are 32°C (dry bulb) and 80% percentage saturation. Heat gains through the fabric of the building are estimated to be 3400 W. Gains from electrical equipment (including lighting) are 1.3 kW and when fully operational 20 people are exercising vigorously. The conditioned air entering the room comprises 20% fresh air and 80% recirculated air. The fan power and heat transfer to and from the ducts may be neglected. The evaporator of the chiller has an apparatus dew point of 8°C and a coil bypass factor of 10%. For an individual exercising vigorously the load may be taken as 210 W Sensible heat and 315 W latent heat. (a) Show each process and clearly label the state points on the psychometric chart provided. (7 marks) Calculate: (i) the airflow through the chiller. (ii) the rate of moisture removal in the chiller. (iii) the rate of heat removal in the evaporator of the chiller (iv) the rate of heat supplied in the heater. (2 marks) (2 marks) (2 marks) (2 marks) (b) If all other design parameters (including apparatus dewpoint) remain the same, estimate, with justification, the highest value of coil bypass factor at which the air conditioner could meet its specification. Explain why operating under these conditions is undesirable. (6 marks)