EPA 608 Technician Certification High-Pressure Leak Detection and Leak Repair Summary

Under 40 CFR 82.157(c), appliances with 50 or more pounds of ozone-depleting refrigerant must be repaired when the leak rate is over 10 percent for comfort cooling (and other appliances), 20 percent for commercial refrigeration, and 30 percent for industrial process refrigeration.

Wrong choices

• 30 percent: 30 percent is the trigger for industrial process refrigeration.
• 20 percent: 20 percent is the trigger for commercial refrigeration.
• 35 percent: 35 percent was an older trigger rate that no longer applies.

Supermarket and cold-storage systems are commercial refrigeration. With 50 or more pounds of ozone-depleting refrigerant, leaks must be repaired when the leak rate exceeds 20 percent per year.

Wrong choices

• 30 percent: 30 percent is the trigger for industrial process refrigeration.
• 15 percent: 15 percent was an older comfort cooling trigger.
• 10 percent: 10 percent is the trigger for comfort cooling and other appliances.

Under 40 CFR 82.157(d), leaks must be repaired within 30 days of adding refrigerant to an appliance that exceeds the trigger rate, or 120 days if an industrial process shutdown is needed.

Wrong choices

• 90 days: 90 days is not the standard repair period.
• 10 days: 10 days is the time limit for the follow-up verification test, not the repair.
• 1 year: One year is the time to complete a retrofit or retirement plan.

Refrigerant carries oil, so oil traces around joints, fittings, and hermetic compressor connections are a common sign of a leak. Excessive superheat is another sign.

Wrong choices

• A clean, dry condenser coil: A clean, dry coil is not a sign of a leak.
• Low noise from the compressor: Compressor noise level is not a typical leak sign.
• Frost on the outside of the recovery cylinder: Frost on a recovery cylinder is normal during recovery and is not a leak sign on the system.

EPA's test topics stress the need to leak test before charging or recharging equipment, so refrigerant is not lost through a leak that could have been found first.

Wrong choices

• Never; the compressor will show any leaks: A compressor does not reveal leaks.
• Only once a year in the spring: Leak testing is needed before charging, whatever the season.
• Only after the system has been fully charged: Testing after charging wastes refrigerant if there is a leak.

For industrial process refrigeration (chemical plants, industrial ice machines, ice rinks, and similar), the leak repair trigger is 30 percent per year for appliances with 50 or more pounds of ozone-depleting refrigerant.

Wrong choices

• 10 percent: 10 percent is the trigger for comfort cooling.
• 20 percent: 20 percent is the trigger for commercial refrigeration.
• 35 percent: 35 percent was the older trigger before the 2016 rule.

Under 40 CFR 82.157(h), an owner who chooses to retrofit or retire must create a written plan within 30 days and complete the work within one year of the plan's date, unless granted more time.

Wrong choices

• Retire it within 10 days with no plan: The rule requires a written plan, and 10 days is not the deadline.
• Nothing, as long as refrigerant is added each month: Topping off a leaking appliance does not meet the rule.
• Send a letter to EPA within 1 year: A letter to EPA is not the requirement.

Under 40 CFR 82.157(b), the owner must calculate the leak rate every time refrigerant is added, except right after a retrofit, a new installation, or a seasonal variance. The technician must give the owner a record of the amount added.

Wrong choices

• Only when it is disposed of: Disposal is not when leak rates are calculated.
• Only when the appliance stops cooling: Waiting until the appliance fails is too late.
• Once every 5 years: The rule requires a calculation each time refrigerant is added.

When refrigerant leaks out, less refrigerant reaches the evaporator. It boils off early and the vapor picks up extra heat, so superheat becomes excessive. EPA lists this as a sign of leakage in high-pressure systems.

Wrong choices

• Ice-cold liquid line: This is not a typical sign of a leak.
• Very low superheat: Very low superheat often means overcharge or too much refrigerant flow, not a leak.
• High suction pressure: A leak usually lowers suction pressure.

40 CFR 82.157 applies to appliances with a full charge of 50 or more pounds of a CFC or HCFC refrigerant (or a blend containing one). Appliances with only substitute refrigerants are not covered by this section; HFC appliances now fall under Part 84.

Wrong choices

• 5 pounds or more: 5 pounds is the small appliance limit.
• 15 pounds or more: 15 pounds is the threshold in the newer Part 84 rule for HFCs, not Part 82.
• 200 pounds or more: 200 pounds is a break point in the evacuation table, not leak repair.