How to find power required for adiabatic compressor? Problem - Air enters an adiabatic compressor at 20 C and 1bar. The volumetric flow rate of air is 1 m3/s and it exits at 200 C. Determine the power required if the isentropic efficiency of the compressor is 80%. Density of water = 1000 kg/m^3 Mass flow rate m = 1 m^3/s * 1000 kg/m^3 = 1000 kg/s I know that power output is calculated by m Cp (T2 - T1) But what is meant by power required? Is it same as power output or is it power input? If it is power output, then we can calculate it using m Cp (T2 - T1) If it is power input, then can we use work required = power output/(isentropic efficiency) ? The problem involves a range of temperatures. I have to use the values of density, Cp and any other constants needed at what temperature? Initial? Final? Average?