Coast Guard Exams
Question 41Refrigeration/AC - 1st Asst/Chief70% to pass

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?

AI Explanation
The correct answer is D) liquid recovery using a liquid pump, followed by vapor recovery using a vacuum pump based recovery unit. The EPA requires that refrigerants be recovered using a combination of liquid and vapor recovery methods to ensure complete recovery and to meet environmental regulations. For a low-pressure chiller with more than 500 lbs of refrigerant, using a liquid pump for the initial liquid recovery, followed by a vacuum pump based vapor recovery unit, is the most cost-effective method to fully recover the refrigerant and comply with EPA requirements. The other options are less effective or do not fully meet the EPA regulations. Option A, using only a vapor recovery machine, may not be sufficient to recover all the liquid refrigerant. Option B, using a vapor recovery unit followed by a liquid pump, is less efficient than the recommended approach. Option C, using only a liquid pump, would not recover the vapor portion of the refrigerant, which is also required.