The most cost-effective method of recovering refrigerant from a low pressure chiller with more than 500 lbs of refrigerant and to meet EPA requirements is to recover the refrigerant using what protocol?

Correct Answer: Option B — liquid recovery using a liquid pump, followed by vapor recovery using a vacuum pump based recovery unit

Extracting bulk liquid first drastically accelerates the recovery process on large low-pressure chillers, followed by a vacuum-based unit to recover remaining refrigerant vapor to required EPA evacuation thresholds.