Leak Rate on a 75-Pound R-22 System
A Type II technician maintains a 75-lb R-22 comfort-cooling system manufactured in 2005. Records show 12 lb of R-22 was added in June and 10 lb in August; no other refrigerant was added in the past 12 months. The owner wants to replace only the compressor and keep adding R-22 as needed. The system has a chronic leak at an evaporator coil joint. You have recovery equipment and a vacuum pump.
1. Calculate the 12-month leak rate and determine whether repair is required.
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The leak rate is the refrigerant added over 12 months divided by the system charge: (12 lb + 10 lb) / 75 lb = 22 / 75 = 0.293, or about 29.3%. This is a comfort-cooling appliance with a charge of 50 lb or more, so the leak-rate threshold is 15%. Because 29.3% exceeds 15%, the system is subject to the leak-repair requirements: repair the leak within 30 days, or retrofit or retire the appliance if repair is not possible. The owner cannot simply keep adding refrigerant without addressing the leak-repair obligation.
2. What evacuation level applies if you recover the charge to repair the evaporator joint?
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The system was manufactured in 2005, so it is a high-pressure appliance manufactured after November 15, 1993. The EPA minimum evacuation level is 10 inches Hg vacuum. Follow any deeper manufacturer specification, and use dry nitrogen for pressure testing rather than air. Recover the R-22 first, repair the joint, evacuate, and verify the vacuum holds before recharging.
3. The owner argues that R-22 is being phased out, so the leak-repair rules should not apply. How do you answer?
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The phaseout of R-22 production and import affects supply, not the leak-repair and venting prohibitions. R-22 is an HCFC, and reclaimed or recycled R-22 may still be used in existing equipment, but the appliance is still subject to the Section 608 leak-repair rules because it contains 50 lb or more of refrigerant and exceeded the 15% comfort-cooling threshold. The owner must repair the leak, or retrofit or retire the system, rather than treating the phaseout as an exemption.