Evaporative, forced draft: at best you can estimate for "fully known" operating condiiton: That is run all the fans fulll speed, measure air dry bulb and wet bulb in and out, look up enthalpy change on a psychometric chart. Once you have heat, take out compressor power net of any oil cooling or similar that adds to the heat transferred to the condenser.
But its just as easy usually to measure the refrigerant conditions and the motor input HP and look up TR for the compressor, or a similar machine, in the manufacturers data for the measured Suction and Discharge conditions.
