EPA 608 Certification Type II: High-Pressure Appliances Syllabus

Type II: High-Pressure Appliances syllabus — full chapter and topic list

Expand any chapter to see its topics and sub-topics. This is the whole examinable outline for Type II: High-Pressure Appliances in EPA 608 Certification, not a summary of it.

1. 1

   High-Pressure Appliance Definition and Refrigerants

   3 topics

   • High-Pressure Refrigerant Classification
     • Refrigerants with boiling points between -50 C and 10 C (R-22, R-410A, R-407C, R-134a)
     • Very high-pressure refrigerants (R-13, R-503) and special handling
   • Typical Type II Equipment (residential/commercial split systems, heat pumps, supermarket racks, water-cooled chillers)
   • Pressure-Temperature Relationships and PT Charts
2. 2

   Recovery and Evacuation Requirements

   4 topics

   • Required Evacuation Levels (inches of mercury vacuum)
     • Levels for appliances with charge less than 200 lbs vs 200 lbs or more
     • Differences for equipment manufactured before and after Nov 15, 1993
     • Reduced requirements for systems with known leaks
   • Liquid vs Vapor Recovery and Speeding Up Recovery
   • Recovering Refrigerant from a System with a Burned-Out Compressor
   • Non-Condensable Gases and Their Effect on Recovery and Pressure Readings
3. 3

   Leak Detection and Repair Requirements

   3 topics

   • Leak Repair Provisions for Appliances 50 lbs and Over
     • Applicable leak rate thresholds by equipment type (commercial vs comfort cooling)
     • Timeframe to repair or develop a retrofit/retirement plan
     • Verification tests (initial and follow-up) after repair
   • Leak Detection Methods
     • Electronic leak detectors, halide torch, soap-bubble, fluorescent dye
     • Standing pressure/vacuum tests with nitrogen
   • Automatic Leak Detection Systems for Large Equipment
4. 4

   Charging, Servicing, and System Cleanup

   4 topics

   • Proper Charging Procedures and Subcooling/Superheat Verification
   • System Cleanup After a Hermetic Compressor Burnout (filter-drier use)
   • Use of Nitrogen for Leak Testing and Brazing Purge
   • Avoiding Cross-Contamination and Refrigerant Mixing

Type II: High-Pressure Appliances flashcards for EPA 608 Certification

24 of 50 cards from the Type II: High-Pressure Appliances deck — real questions with worked answers.

1. Under EPA Section 608, what defines a Type II (high-pressure) appliance?

   An appliance that uses a refrigerant with a boiling point between -50°C and 10°C (about -58°F and 50°F) at atmospheric pressure, such as R-22, R-410A, R-407C, R-134a, and R-404A. Type II covers high-pressure refrigerants and equipment.

2. Which refrigerant pressure class do common HVAC refrigerants like R-22 and R-410A belong to for EPA 608 certification?

   They are high-pressure refrigerants, which fall under Type II certification (and very-high-pressure refrigerants like R-410A also require Type II knowledge).

3. What distinguishes a very-high-pressure refrigerant from a standard high-pressure refrigerant?

   A very-high-pressure refrigerant has a boiling point below -50°C (-58°F) at one atmosphere, such as R-410A or R-13. Standard high-pressure refrigerants (e.g., R-22) boil between -50°C and 10°C. Both are serviced under Type II rules.

4. List four types of equipment a Type II technician typically services.

   Residential and commercial split-system air conditioners, heat pumps, supermarket refrigeration racks, and water-cooled chillers (plus packaged AC and process refrigeration).

5. What is the pressure-temperature (PT) relationship for a refrigerant in a saturated (mixed liquid/vapor) state?

   For a pure refrigerant in saturation, there is a fixed one-to-one relationship: each saturation pressure corresponds to exactly one saturation temperature. A PT chart lists these matched values for each refrigerant.

6. How is a PT chart used to find the boiling/condensing temperature of a refrigerant?

   Measure the system pressure with a gauge, then read across the PT chart for that refrigerant to find the corresponding saturation temperature. That temperature is the refrigerant's boiling (low side) or condensing (high side) temperature.

7. Why can't a single PT chart be used for all refrigerants?

   Each refrigerant has a unique pressure-temperature relationship, so a given pressure corresponds to different temperatures for different refrigerants. You must use the column or chart for the specific refrigerant in the system.

8. On a PT chart, if R-22 reads 69 psig on the low side, approximately what saturated temperature does that represent?

   About 40°F. (R-22 saturation: 40°F corresponds to roughly 68-69 psig.) This is a typical evaporator condition used to check operation.

9. What recovery vacuum level (inches of mercury) is required for a Type II high-pressure appliance with a compressor 'normally containing' less than 200 lbs of refrigerant, using equipment made after Nov 15, 1993?

   Recover to 10 inches of mercury vacuum (10 in. Hg).

10. What recovery vacuum level is required for a high-pressure appliance containing 200 lbs or more of refrigerant, using recovery equipment manufactured after Nov 15, 1993?

    Recover to 15 inches of mercury vacuum (15 in. Hg).

11. What recovery vacuum level is required for high-pressure appliances using recovery equipment manufactured BEFORE Nov 15, 1993?

    0 inches of mercury (0 in. Hg) — i.e., recover until the system reaches atmospheric pressure (0 psig). Older equipment has a less stringent requirement.

12. For very-high-pressure appliances, what is the required recovery level?

    0 psig (atmospheric pressure). Very-high-pressure refrigerants are recovered to 0 psig regardless of equipment age.

13. What is the difference between vapor (gas) recovery and liquid recovery?

    Vapor recovery pulls refrigerant out as a gas through the recovery machine's compressor; it is slower. Liquid recovery transfers refrigerant in liquid form (often by push-pull), which is much faster for large charges.

14. Describe the push-pull method of refrigerant recovery and when it is used.

    The recovery machine pulls vapor from the recovery cylinder and pushes (discharges) it into the appliance, forcing liquid refrigerant out of the appliance and into the cylinder. It is used for systems with large liquid charges (generally 10-15 lbs or more) to speed recovery.

15. Name three ways to speed up the refrigerant recovery process.

    Recover liquid first (or use push-pull), keep recovery hoses short and large-diameter, cool the recovery cylinder (and/or warm the appliance), and remove the valve cores / use full-port valves to reduce restriction.

16. Why does cooling the recovery cylinder speed up recovery?

    A cooler cylinder has a lower internal pressure, increasing the pressure difference between the appliance and the cylinder so refrigerant moves into the cylinder faster.

17. Why is recovering refrigerant from a system with a burned-out (hermetic) compressor more difficult?

    The recovered refrigerant is contaminated with acid, moisture, and combustion byproducts, which can damage the recovery machine and contaminate the recovery cylinder.

18. What special equipment precaution is recommended when recovering refrigerant from a burned-out compressor?

    Install an acid-rated filter-drier in the recovery line ahead of the recovery machine to protect it, and recover into a dedicated/marked cylinder so contaminated refrigerant is sent for reclamation, not reused.

19. After recovering refrigerant from a burnout, can that refrigerant be charged back into the same system?

    No — contaminated refrigerant from a burnout must be sent to a certified reclaimer (reclaimed to ARI-700 purity) or properly destroyed; it must not be recharged without reclamation.

20. What is a non-condensable gas in a refrigeration system, and what is the most common one?

    A non-condensable is a gas that does not condense at system conditions and collects in the high side/condenser. The most common is air (which also brings in moisture), usually from incomplete evacuation.

21. How do non-condensable gases affect high-side pressure readings?

    They raise the head (condenser) pressure above what the PT chart predicts for the refrigerant's condensing temperature, causing artificially high discharge pressure and reduced efficiency.

22. How can a technician check for non-condensables in a system?

    Let the system sit off until it reaches ambient temperature, then compare the static pressure to the PT chart value for that ambient temperature. If actual pressure is higher than the chart value, non-condensables (air) are present.

23. Why do non-condensable gases slow down and complicate refrigerant recovery?

    Air in the recovery cylinder raises cylinder pressure, reducing the pressure differential and increasing required recovery time; it can also push the cylinder toward overpressure and contaminate the refrigerant.

24. Under EPA leak-repair rules, which appliances are subject to leak repair requirements based on charge size?

    Appliances normally containing 50 or more pounds of refrigerant are subject to the leak repair provisions.

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