1. Technician’s Guide and Workbook for the EPA Section 608 Test Section 8: Type 2 Test Part 1

2. High Pressure Appliance Leak Detection
Topics in this section:
Signs of leakage in high-pressure systems (excessive superheat, traces of oil for hermetic systems)
Need to leak test before charging or recharging equipment
Large system leakage rules
Leak rates for large systems

3. Signs of Leakage
Signs of leakage in a high-pressure HVAC system include:
Warm airflow from supply registers in cooling mode or cold air from registers in heat pump heating mode.
Relatively cool condenser discharge air (close to ambient temperature).
Ice buildup on evaporator or copper lines.
Buildup of refrigerant oil on fitting, access valve, coil or refrigerant tubing.
Low refrigerant pressures on the high and low side.
High superheat value.
Low sub-cooling value.

4. Likely Places to Find Leaks
Valves.
Flare fittings.
Wherever copper tubing may be touching something it can rub against.
Rusted out receivers.
Non-hermetic compressor rotating shafts.
Non-hermetic compressor head gaskets.
Evaporator coils.
Condenser coils.
Expansion devices.
Rusty filters/dryers.

5. Leak Test Before Charging (1)
Leak testing should be performed using an electronic leak detector that is designed to detect the specific refrigerant contained in the system. When a system contains no refrigerant, a trace amount of that system’s refrigerant may be added to a nitrogen (or other inert gas) charge for use with a leak detector. Florescent dye, when compatible with the refrigeration system, can be used to identify hard to find small leaks. The dye becomes bright when a black (UV) light is used to light up the equipment. This works especially well in dark areas or at night.

6. Leak Test Before Charging (2)
Simple soap bubbles can also be used to identify an exact leak location. Soap bubbles are also easy to use: simply paint the surface area with the soap solution and bubbles will appear as the vapor/gas comes out of the refrigeration surface or part at the point of the leak. A vacuum pump can be used to verify that there are no leaks before a system is charged. This method is highly recommended since a vacuum is required before adding refrigerant to any system that has been open for repairs. This procedure was covered in the Core section of the Guide and Workbook.

7. Large System Rules (1)
As of January 1, 2019, the following protocols apply to systems that contain over 50 pounds of refrigerant:
The leak rate must be calculated every time refrigerant is added to the system.
Verification tests must be performed on industrial process refrigeration, commercial refrigeration, and comfort cooling systems. Revised EPA leak rate thresholds for these applications:
30% for industrial process refrigeration (IPR)—lowered from 35%.
20% for commercial refrigeration—lowered from 35%.
10% for comfort cooling—lowered from 15%.
A certified technician must perform leak inspection to identify necessary repairs.
The repair must bring the system leak rate below the threshold; this must be demonstrated when calculating the leak rate upon refrigerant addition.

8. Large System Rules (2)
The technician must demonstrate that leaks were successfully repaired on the appliance, including:
Initial verification tests done before refrigerant is added.
Follow-up verification done after refrigerant is added.
If either the initial or follow-up verification test indicates that repairs were not successful, additional repairs and verification tests must be undertaken within a 30-day period until the EPA-established leak rate thresholds are satisfied.
Periodic leak inspections are required on appliances repaired to meet threshold leak rates:
Periodic leak inspections must be conducted by a certified technician unless the appliance has an automatic leak detection system.

9. Large System Rules (2)
All visible and accessible components of an appliance (piece of equipment) must be inspected. Examples of areas not considered visible include components that are insulated, under ice, underground, in walls, inaccessible, elevated 2 meters (6.5’) or more above a support surface, or in a location where inspection would be unsafe.
Equipment that contains refrigerants regulated by EPA Section 608 that cannot be repaired must be scrapped or retired (mothballed) within 12 months.
Equipment that contains refrigerants not regulated by EPA Section 608 that cannot be repaired must be scrapped or retired (mothballed) within 18 months.
Records of leakage must be kept by the equipment owner for 3 years.
A report must be filed with the EPA by the equipment owner (or designated agent) on all equipment containing EPA Section 608 regulated refrigerants that leaks 125% or more of its total charge in one year.

10. Large System Leak Threshold Limits (1)
The leak rate is the rate at which an appliance is losing refrigerant as measured between refrigerant charges. The following rules apply for systems containing 50 pounds or more of refrigerant:
Topping off a system’s refrigerant triggers the requirement to establish the leak rate.
The time allowed to repair the leak is 30 days, with a follow-up verification required within 10 days of repair completion. Thus, a minimum of two leak tests are required.
The 30-day deadline for repairs can be extended for the following reasons:
Federal, state or local requirements make the repair impossible within the 30-day period.
A required component is not available within the 30-day period.
Equipment is in an area of radiological contamination .

11. Large System Leak Threshold Limits (2)
If repairs are not done to leaking equipment, it must be retired within 12 months. If the equipment is exempt from the venting prohibition, the owners have 18 months to retire it.
If equipment loses more than 125% of its charge in one year, the equipment owner must submit a report to the EPA.
Deadlines for Radiological Contamination Areas Can Be Extended

12. Recovery Techniques Topics in this section:
Recovering liquid at the beginning of the recovery process speeds up the process
Methods for speeding recovery
Methods for reducing cross-contamination and emissions when a recovery or recycling machine is used with a new refrigerant
Need to wait a few minutes after reaching required recovery vacuum to see if system pressure rises (indicating that there is still liquid refrigerant in the system or in the oil)

13. Methods for Speeding Recovery
Assuming the selection of recovery equipment designed for high fluid flows that can handle both fluid and vapor the following can decrease recovery time:
Remove all Schraeder-valve cores.
Start the recovery process on the liquid side, then open the vapor side after a few minutes. Note: When the receiver is below the condenser, the refrigerant should be recovered from the receiver outlet.
Open recovery cylinder valves wide open. In fact, make sure all refrigerant valves are wide open.
Use a short, large-diameter, open hose designed for removing refrigerant from the recovery machine outlet to the liquid connection of the recovery cylinder (Thus, removing the liquid refrigerant).
Keep recovery equipment in the shade when possible.
Recovery tanks can be rotated or held in an ice bath.

14. Recovery Cylinders
Recovery cylinders need to be able to hold 20% more refrigerant than the amount being recovered.

15. Methods for Reducing Cross-Contamination and Emissions
Make sure refrigerants are never mixed. This can be accomplished by developing the following best practices:
Purge the reclaimer after each use and change the oil.
Change the reclaimer filter after every use (or at a minimum when changing refrigerants).
Purge gauge sets before connecting, or better yet, have gauge sets designated for each refrigerant.
Never mix refrigerants in cylinders.
Pull a vacuum in the empty recovery cylinder.

16. Need to Wait During Vacuum Procedure
Wait a couple of minutes after reaching the reclaiming target vacuum value. Refrigerant entrained in oil may take a few minutes to separate at the reclaiming vacuum pressure of 4 inches of mercury in a vacuum.

17. Recovery Requirements
Topics in this section:
Evacuation requirements for high-pressure appliances in varying situations:
Disposal
Major versus non-major repairs
Leaky appliance trigger rate
Appliance (or component) containing less versus more than 200 pounds
Recovery/recycling equipment built before versus after November 15, 1993
Definition of "major" versus non-major repairs
Prohibition on using system-dependent recovery equipment on systems containing more than 15 pounds of refrigerant

18. Evacuation Requirements for High-Pressure Systems (1)
HVAC servicing companies must keep records for disposed appliances containing between 5 and 50 pounds of refrigerant for 3 years.  
As noted in an earlier chapter, equipment that typically enters the waste stream with its refrigerant charge intact—e.g., motor vehicle air conditioners (MVACs), household refrigerators and freezers, and window unit air conditioners—is subject to special safe disposal requirements:
The final person in the disposal chain (such as a scrap metal recycler or landfill owner) is responsible for ensuring that refrigerant is recovered from equipment before its final disposal.
If the final person in the disposal chain accepts an appliance that no longer holds a refrigerant charge, that person is responsible for maintaining a signed statement from the person who dropped off the appliance. The signed statement must include the name and address of the person who recovered the refrigerant and the date that the refrigerant was recovered. Alternatively, this could be a copy of a contract stating that the refrigerant will be removed prior to delivery.

19. Evacuation Requirements for High-Pressure Systems (2)
The EPA does not mandate a sticker as a form of verification that the refrigerant has been removed prior to disposal (see Figure 31). Such stickers do not relieve the final disposer of their responsibility to recover any remaining refrigerant in the appliance unless the sticker consists of a signed statement that includes the name and address of the person who recovered the refrigerant and the date that the refrigerant was recovered.
Individuals removing refrigerant from small appliances, MVACs, and MVAC- like air conditioners, when preparing them for disposal, are not required to be certified technicians. However, the equipment used to recover refrigerant from appliances prior to their final disposal must meet the same performance standards as refrigerant recovery equipment used for servicing.
The EPA no longer requires a person involved in the final disposal of appliances to certify to an EPA regional offices that the individual has obtained and is properly using EPA-certified refrigerant recovery equipment.

20. Major or Minor Repair?
Major repairs: Maintenance, service, or repair that involves removal of the appliance compressor, condenser, evaporator, or auxiliary heat exchanger coil is considered a major repair.

21. System Dependent Recovery
EPA rules prohibit the usage of system-dependent recovery equipment on systems containing more than 15 pounds of refrigerant.