Q2- The economizer shown in figure below is designed to maintain temperature in a room. One...

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Q2- The economizer shown in figure below is designed to maintain temperature in a room. One of economizer inlets (return air inlet) returns the air from the room, in which the temperature is maintained at 23 C. Another inlet (fresh air inlet) takes the 5 C air from the outdoor. Air streams have total flow rates of 1.2 m3/s and 4.8 m3/s at fresh air and return air inlets, respectively. The mixed air finally exits from the supply air outlet at a temperature of 35 C. As shown in the figure below, an electric resistance heating system is used for heating up the inlet airs. a) Determine the amount of heat needs to be produced by the electrical heater. b) Assuming an Energy Efficiency Ratio of 8 BTU/Wh, determine the heater energy input c) Calculate the Coefficient of Performance (COP). d) Assuming a total pressure drop of 15 kPa in the economizer and the ductwork, calculate the required fan power for supplying the air into the room (Fan efficiency: 80%). e) Explain briefly the advantage of air recovery from the room over using 100% fresh air? Note: air density 1.2 kg/m air Cp= 1 kJ/kg.C Q2- The economizer shown in figure below is designed to maintain temperature in a room. One of economizer inlets (return air inlet) returns the air from the room, in which the temperature is maintained at 23 C. Another inlet (fresh air inlet) takes the 5 C air from the outdoor. Air streams have total flow rates of 1.2 m3/s and 4.8 m3/s at fresh air and return air inlets, respectively. The mixed air finally exits from the supply air outlet at a temperature of 35 C. As shown in the figure below, an electric resistance heating system is used for heating up the inlet airs. a) Determine the amount of heat needs to be produced by the electrical heater. b) Assuming an Energy Efficiency Ratio of 8 BTU/Wh, determine the heater energy input c) Calculate the Coefficient of Performance (COP). d) Assuming a total pressure drop of 15 kPa in the economizer and the ductwork, calculate the required fan power for supplying the air into the room (Fan efficiency: 80%). e) Explain briefly the advantage of air recovery from the room over using 100% fresh air? Note: air density 1.2 kg/m air Cp= 1 kJ/kg.C