An air-conditioner using R-134a as the working as the working fluid maintains a space at a constant temperature of 23 degrees celsius while rejecting heat to the outside at 37 degrees celsius. The rate of heat gain in the space is 5.0kW. The refrigerant enters the compressor as a saturated vapour at 400kPa and at a rate of 20l/min and leaves at 1.2MPa and 70 degrees celsius. The compressor loses heat to the surroundings at the rate of 100W. The temperature surrounding the compressor is Tb = 27 degrees celsius.

a) Determine the Coefficient of Performance (COP) of the machine.

b) Determine theoretical maximum COP of the machine.

c) Calculate the rate of entropy generation.