Refrigerant 134a enters the compressor of a vapor compression heat pump at 15 psi and 0 °F and is compressed to 160 psi and 160 °F. Liquid enters the expansion valve at 160 psi and 95 °F. At the valve exit the pressure is 15 psi. Determine 1) The isentropic compressor efficiency 2) The coefficient of performance. 3) Draw the cycle on a T-S diagram.