During normal operation, traditionally, how has most of the refrigerant released to the atmosphere from low-pressure systems?

Correct Answer: Option B — through the purge unit vent

Low-pressure chillers operate below atmospheric pressure, causing non-condensables and refrigerant vapor to leak into the purge unit. Under EPA and marine environmental standards, continuous purging of accumulated air results in the gradual release of refrigerant trapped in the purge discharge vent.