Question 48Refrigeration & AC - Assistant Engineer

The correct answer is B) liquid recovery using a liquid pump, followed by vapor recovery using a vacuum pump based recovery unit. This is the most cost-effective method to meet EPA requirements for recovering refrigerant from a low-pressure chiller with more than 500 lbs. of refrigerant. The EPA requires that all refrigerant be recovered to the maximum extent possible before equipment is serviced or disposed of. Using a liquid pump first to recover the liquid refrigerant, followed by a vacuum pump based recovery unit to capture the remaining vapor, ensures the most complete recovery and is the most efficient approach. The other options are not as effective - option A would only recover the vapor, leaving liquid refrigerant behind, option C would recover the vapor first but then struggle to extract the remaining liquid, and option D using only a liquid pump would not be able to fully recover the vapor portion of the refrigerant.