12.2 Type I vs Type II vs Type III: Side-by-Side Review

EPA 608 Technician Certification Exam

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1 Introduction to EPA 608 Certification

1.1 What EPA 608 Is and Who Needs It 1.2 Exam Format, Scoring, and Administration 1.3 How to Study for EPA 608

2 Regulations and the Clean Air Act

2.1 Clean Air Act Overview 2.2 Penalties and Enforcement 2.3 Montreal Protocol and International Agreements 2.4 AIM Act and HFC Phasedown Schedule 2.5 SNAP Program and Refrigerant Transitions

3 Refrigerants and Ozone Science

3.1 The Science of Ozone Depletion (ODP and GWP) 3.2 Refrigerant Classification, ASHRAE Numbering, and Safety Groups 3.3 Common Refrigerants: Properties, Applications, and Phaseout Status 3.4 Refrigerant Blends: Glide, Fractionation, and Liquid Charging

4 The Refrigeration Cycle

4.1 The Basic Refrigeration Cycle 4.2 System Components in Detail 4.3 Heat Transfer and Pressure-Temperature Relationships

5 Refrigerant Safety and Handling

5.1 Refrigerant Hazards and Health Effects 5.2 Safe Handling Practices, PPE, and Cylinders 5.3 A2L (Mildly Flammable) Refrigerant Safety

6 Recovery, Recycling, and Reclaiming

6.1 The Three Rs: Recover, Recycle, Reclaim 6.2 Recovery Equipment Requirements 6.3 Required Levels of Evacuation 6.4 Refrigerant Sales Restrictions and Recordkeeping

7 Leak Detection and Repair

7.1 Leak Detection Methods 7.2 Leak Repair Requirements and Trigger Rates 7.3 Leak-Rate Calculation, Recordkeeping, and Reporting

8 Type I — Small Appliances

8.1 What Counts as a Small Appliance 8.2 Type I Recovery Requirements 8.3 Type I Procedures, Access Valves, and the Open-Book Exam

9 Type II — High-Pressure Appliances

9.1 What Type II Covers: High-Pressure System Overview 9.2 Type II Recovery Methods and Required Evacuation Levels 9.3 Leak Detection, the Repair Triggers, and Recordkeeping 9.4 The R-22 Phaseout, Retrofits, and the Move to Lower-GWP A2Ls

10 Type III — Low-Pressure Appliances

10.1 Low-Pressure System Fundamentals 10.2 Purge Units and Air Management 10.3 Type III Recovery and Procedures 10.4 Type III Leak Testing

11 10. Disposal, Shipping, and Compliance

11.1 Equipment Disposal Requirements 11.2 Refrigerant Shipping and Transport 11.3 Compliance Checklist and Best Practices

12 Final Review and Exam Strategy

12.1 High-Yield Core Section Review 12.2 Type I vs Type II vs Type III: Side-by-Side Review 12.3 How the Exam Works and Exam-Day Strategy

12.2 Type I vs Type II vs Type III: Side-by-Side Review

Key Takeaways Explain This Topic AI

Type I covers small appliances (factory-sealed, 5 lbs or less): refrigerators, freezers, window ACs, dehumidifiers, and vending machines.

Type II covers medium-, high-, and very-high-pressure systems (residential/commercial AC, heat pumps, supermarket refrigeration, R-134a chillers) using refrigerants like R-22, R-410A, R-404A, and R-134a.

Type III covers low-pressure systems - centrifugal chillers that run in a vacuum using R-11, R-123, or R-1233zd - and uniquely requires evacuation to 25 mm Hg absolute.

Small-appliance recovery is 90% with the compressor operating and 80% with it inoperative when the recovery equipment was made on or after Nov 15, 1993 (80% with older equipment), or 4 in. Hg; high-pressure evacuation is 0 in. Hg under 200 lbs and 10 in. Hg at 200 lbs or more on post-1993 equipment, for every high-pressure refrigerant.

Universal certification requires passing Core plus all three Type sections; the type sections are distinguished mainly by appliance pressure, recovery efficiency, and evacuation level.

Last updated: October 2026

How the Three Types Are Defined

Every EPA 608 type section maps to a category of appliance defined by its operating pressure and refrigerant charge . Knowing which appliance belongs to which type - and the recovery and evacuation numbers attached to each - is the difference between passing one type section and passing all three for Universal certification. This review puts the three types side by side so the distinctions stop blurring together.

Type I - Small Appliances. A small appliance is factory-sealed (hermetic), fully charged at the factory, and holds 5 pounds or less of refrigerant. Typical examples are household refrigerators and freezers, window air conditioners, dehumidifiers, drinking-water coolers, and vending machines. Because these units are tiny and self-contained, Type I has its own recovery-efficiency rule rather than a vacuum target.

Type II - Medium-, High-, and Very-High-Pressure. Type II covers the bulk of field HVAC: residential and commercial split-system air conditioners, heat pumps, supermarket and commercial refrigeration racks, and process cooling. Common refrigerants include R-22, R-410A, R-404A, R-407C, and the newer A2L blends R-454B and R-32 . R-410A runs at much higher pressure than older R-22 (both are high-pressure refrigerants in EPA's classes), and Type II is where leak-repair thresholds and proper evacuation matter most.

Type III - Low-Pressure. Type III covers centrifugal chillers that operate below atmospheric pressure (in a vacuum) using refrigerants like R-11 (CFC), R-123 (HCFC), and R-1233zd (HFO) . Because these systems run in a vacuum, a leak draws air into the system rather than pushing refrigerant out, which drives Type III's unique purge-unit and evacuation rules.

Recovery Efficiency and Evacuation - The Numbers That Separate the Types

The single most-tested set of facts across the type sections is how clean a system must be at the end of recovery . Type I uses a recovery-efficiency percentage; Types II and III use a vacuum target. Memorize this table - it is the backbone of the type-specific questions:

Appliance category Type Recovery / evacuation requirement

Small appliance, compressor operating (recovery equipment made on/after Nov 15, 1993) I 90% of charge recovered, or 4 in. Hg vacuum

Small appliance, compressor inoperative (or older recovery equipment) I 80% of charge recovered, or 4 in. Hg vacuum

• High-pressure (R-22, R-410A, R-407C...), < 200 lbs charge II 0 in. Hg vacuum (any recovery equipment)
• High-pressure, 200 lbs or more II 10 in. Hg vacuum (post-1993 equipment; 4 in. Hg older)
• Medium-pressure (R-134a...), < 200 / 200+ lbs II 10 / 15 in. Hg vacuum (post-1993 equipment; 4 in. Hg older)
• Very high-pressure II 0 in. Hg vacuum (0 psig)
• Low-pressure III 25 mm Hg absolute

Note the logic. For Type I , a running compressor helps push refrigerant out, so with post-1993 recovery equipment the bar is higher ( 90% ); if the compressor is dead (or the equipment is older), the bar is 80% . For Type II high-pressure appliances the reverse of a "bigger is easier" rule applies: a charge of 200 lbs or more must be pulled deeper — 10 in. Hg with post-1993 equipment — while a smaller one needs only 0 in. Hg . Type III demands the deepest vacuum, 25 mm Hg absolute , because low-pressure chillers boil refrigerant at low pressure and would otherwise lose significant charge.

Other Distinguishing Facts

Leak repair (mostly Type II): Threshold-exceeding leaks on systems with 50+ lbs of ozone-depleting refrigerant (or 15+ lbs of HFC refrigerant under Part 84 since January 1, 2026) must be repaired within 30 days ; thresholds are 10% (comfort cooling), 20% (commercial refrigeration), and 30% (industrial process).

Type I access and disposal: Use a line-tap valve or process tube; the last person in the disposal chain is responsible for recovering refrigerant before scrapping.

Type III purge units: A purge unit removes non-condensable gases (air) that accumulate at the top of the condenser; for a non-major repair that will not be followed by evacuation, technicians pressurize a low-pressure system to no higher than 0 psig before opening it (using heat, not nitrogen, on R-11 and R-123 machines) so air does not rush in.

Refrigerant and Pressure Cues That Reveal the Type

When a question does not name the type outright, the refrigerant usually gives it away. R-11 and R-123 appear only on low-pressure Type III chillers. R-22, R-410A, R-404A, and R-407C point to high-pressure Type II field equipment, with R-410A in the same high-pressure class as R-22 even though it runs roughly 60% higher and uses POE (polyolester) oil instead of mineral oil.

A factory-sealed unit charged to 5 lbs or less is always Type I , regardless of the refrigerant inside. Practicing this "refrigerant-to-type" reflex saves time on the type sections, because once you fix the type you can immediately recall the right recovery or evacuation value from the table above.

Why the Distinctions Matter for Universal

The Universal path is simply Core plus all three type sections scored separately, so the type differences are not academic - each section quizzes the recovery and evacuation rules specific to its appliance class. A candidate who memorizes only one type's numbers and assumes they transfer will miss questions on the other two sections. The safest strategy is to learn the full comparison table as a single block so that, on any question, you decide the type first and then read off the matching requirement. That single habit is what carries strong candidates from one passed type section to a complete Universal certification.

Worked example: A technician must recover refrigerant from a household refrigerator whose compressor has burned out and will not run. What recovery level is required? Because this is a Type I small appliance and the compressor is inoperative , the requirement drops from 90% to 80% of the nameplate charge . If the same technician later evacuates a 300-lb commercial R-22 condenser, that is Type II , and the post-1993 target becomes 10 in. Hg because the charge exceeds 200 lbs. Matching the appliance to the correct type - and then to the correct number - is exactly how the type sections are scored.