Question 150Refrigeration & AC - QMED

The correct answer is A) Those purge units which discharge very little refrigerant with the air being removed. In a low-pressure centrifugal chiller, a high efficiency purge unit is one that is designed to remove non-condensable gases (such as air) from the refrigerant circuit while minimizing the loss of actual refrigerant. This is important because the loss of refrigerant can be costly and environmentally damaging. Answer A correctly describes the key characteristic of a high efficiency purge unit - it discharges very little refrigerant along with the removed air, making it more efficient than purge units that vent a higher percentage of the refrigerant. The other answer choices are incorrect because they do not accurately describe the defining feature of a high efficiency purge unit in a low-pressure centrifugal chiller system.