By steadily circulating a refrigerant at low temperatures through passages in the walls of the freezer compartment, a refrigerator maintains the freezer compartment at -5°C when the air surrounding the refrigerator is at 22°C. The rate of heat transfer from the freezer compartment to the refrigerant is 8000 KJ/h and the power input required is 3200 KJ/h. Determine the coefficient of performance of the refrigerator and compare with the COP of a reversible refrigerator operating between the same reservoirs.