Question 46Refrigeration & AC - Assistant Engineer

The correct answer is 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 centrifugal chillers operate at pressures below atmospheric pressure on the low side. This means that any leaks in the low-pressure side of the system will allow air to be drawn into the system, contaminating the refrigerant. The purge recovery unit is typically fitted to remove this air and other non-condensable gases from the system, maintaining the proper refrigerant charge and preventing issues with chiller performance. The other answer choices are incorrect because: A) is not relevant as evacuation is still possible, B) does not explain the need for a purge unit, and D) is not the primary reason for having a purge unit on a low-pressure chiller.