The ram air pressure and temperature are 1.05 bar and 17˚C. The pressure of air after isentropic compression in the main compressor is 4 bar. This air is now cooled to 27˚C in another auxiliary heat exchanger and then expanded isentropically upto the cabin pressure of 1.01 bar. If the air leaves the cabin at 25 ˚ C and the efficiencies for the main compressor, auxiliary compressor and the cooling turbine are 80 %, 75 % and 80 % respectively; Find : i) Power required to operate the system and ii) COP of the system