At depths greater than 2 meters in Kansas, the wintertime soil temperature is approximately 15 degrees C. A farmer heats his house with a heat pump using R134a, generating a temperature of 32 deg C at the exit of the compressor. The compressor entrance is saturated vapor at 5 bar, and the compressor has an isentropic efficiency of 0.8. The evaporator is buried at a depth of 2 meters. The condenser exit is saturated liquid, and a throttling valve is used between this and the evaporator. Determine the coefficient of performance.