Why is a purge recovery unit typically fitted on low-pressure centrifugal chillers?

Correct Answer: Option C — such a chiller can operate at a pressure below atmospheric pressure on the low side thus drawing in air through any low side leaks

Low-pressure chillers operate below atmospheric pressure during normal cycling, creating a natural vacuum that draws ambient air and moisture past shaft seals and flange gaskets whenever a leak exists, necessitating automatic purge units.