Dear Friends,

As you know in case of centrifugal compressor by closing or opening IGV or Vane we can control evaporator temperature (by controlling suction gas mass flow).

At centrifugal compressors route of oil is separate with refrigerant R11/R134a and also there is not any problem for compressor while IGV be in close situation and suction of compressor decreases.

But I see some chillers with flooded evaporators and semi-hermetic (or screw compressors.

As you know these compressors are different with centrifugal compressors. Specially at semi-hermetic compressors in air-conditioning chillers when suction decrease a lot we have oil escape and also compressor gets warm.

Is it true using semi-hermetic compressors with flooded evaporators ?

Sincerely yours.