EPA Section 608 Universal Certification ExamType III (Low-Pressure Appliances)Hard
A large low-pressure chiller containing 300 lbs of R-11 is being recovered. The EPA requires that the refrigerant be recovered to a specific vacuum level. What is the maximum allowable pressure in the system after recovery, assuming the recovery device was manufactured after November 15, 1993?
- A20 inches of Hg vacuum
- B29.5 inches of Hg vacuum
- C15 inches of Hg vacuum
- D25 inches of Hg vacuum
Show answer & explanationAnswer & explanation
Correct answer: D. 25 inches of Hg vacuum
For low-pressure appliances with a charge of 200 lbs or more, using recovery equipment manufactured after November 15, 1993, the EPA requires evacuation to 25 inches of Hg vacuum (or 25 mmHg absolute if using a micron gauge).
Why the other options are wrong
- A. 20 inches of Hg vacuum is not a specific EPA recovery standard for low-pressure appliances.
- B. 29.5 inches of Hg vacuum (or deeper) is a very deep vacuum, often aimed for during evacuation for dehydration, but not the minimum required for recovery.
- C. 15 inches of Hg vacuum is the standard for smaller low-pressure appliances (less than 200 lbs) with post-1993 equipment.
Low-Pressure Appliance Recovery Standards (Post-93, Large Charge)
EPA regulations specify minimum vacuum levels for refrigerant recovery from low-pressure appliances, which vary based on the appliance's refrigerant charge size and the recovery equipment's manufacturing date.
- Post-1993 equipment is more efficient.
- 200 lbs or more charge: 25 inches Hg vacuum.
- Less than 200 lbs charge: 15 inches Hg vacuum.
Memory trick: Two hundred pounds or more, twenty-five is the score!