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

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 - High-Pressure 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. Very-high-pressure refrigerants such as R-410A behave differently from older R-22, 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:

Note the logic. For Type I, a running compressor helps push refrigerant out, so the bar is higher (90%); if the compressor is dead, the bar drops to 80%. For Type II high-pressure, larger charges (over 200 lbs) are allowed a less aggressive vacuum because they are harder to fully evacuate. 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 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; before opening a low-pressure system, technicians first pressurize it to 0 psig 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 flagged as very-high-pressure because it runs roughly 60% higher than R-22 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.