11.2 Type I, II, III Quick-Reference Review
Key Takeaways
- Type I: 5 lbs or less, 90%/80% recovery, 4" Hg vacuum, line tap valves
- Type II: high/very-high pressure, 0 psig evacuation, push-pull recovery, 10%/20%/30% leak triggers
- Type III: low-pressure (vacuum), 25 mm Hg absolute, rupture disc at 15 psig, purge units, eddy current
- Universal certification requires passing all four sections (Core + Type I + II + III)
- Know the equipment, refrigerants, recovery levels, and special concerns for each type
Last updated: March 2026
11.2 Type I, II, III Quick-Reference Review
Use this section as a rapid-fire review of the most critical distinctions between each certification type.
Type I (Small Appliances) — Key Facts
| Topic | Key Information |
|---|---|
| Definition | Factory-sealed, hermetically sealed, 5 lbs or less |
| Examples | Household fridges/freezers, window AC, dehumidifiers, vending machines |
| Recovery (compressor ON) | 90% of charge OR 4-inch Hg vacuum |
| Recovery (compressor OFF) | 80% of charge OR 4-inch Hg vacuum |
| System-dependent limit | 15 lbs or less |
| Trapped refrigerant | Heat with blanket (no flame), tap with rubber mallet |
| Old refrigerants | Pre-1950: SO2, methyl formate — do NOT use standard equipment |
| Access | Line tap valve, process tube |
| Disposal | Last person in chain is responsible |
| MVAC-like | Covered under Section 608 (not 609) |
Type II (High/Very High-Pressure) — Key Facts
| Topic | Key Information |
|---|---|
| Systems | Residential/commercial AC, heat pumps, commercial refrigeration |
| Evacuation | 0 psig (10" Hg vacuum for high-pressure; 0 psig for very high) |
| Key refrigerants | R-22, R-410A, R-404A, R-407C, R-134a, R-454B, R-32 |
| R-410A vs R-22 | R-410A ~60% higher pressure; uses POE oil (not mineral) |
| Oil change pressure | Must be at 5 psig or below |
| Push-pull recovery | For large systems — liquid displacement method |
| Charging | Zeotropic blends (R-407C) = liquid only; liquid-charge R-410A |
| Leak triggers | 10% comfort / 20% commercial / 30% industrial |
| Repair timeline | 30 days from discovery |
| R-22 status | No new production since 2020; only reclaimed/recycled |
Type III (Low-Pressure) — Key Facts
| Topic | Key Information |
|---|---|
| Systems | Centrifugal chillers (100-10,000+ tons) |
| Key refrigerants | R-11 (CFC), R-123 (HCFC, B1), R-1233zd (HFO) |
| Boiling point | Above 50°F at atmospheric pressure |
| Operating condition | Below atmospheric (in vacuum) |
| Evacuation | 25 mm Hg absolute (newer) or 25" Hg vacuum (older) |
| Before opening | Pressurize to 0 psig first |
| Charging | Liquid into the evaporator |
| Rupture disc | Bursts at 15 psig — one-time use |
| Purge unit | Removes NCGs from top of condenser; 99%+ efficiency |
| Leak direction | Air enters system (not refrigerant escaping) |
| Tube failure | Water enters evaporator; causes acid/copper plating |
| Oil sump heater | Must stay ON during shutdown |
| Eddy current test | Non-destructive tube inspection |
Universal Quick Comparison
| Feature | Type I | Type II | Type III |
|---|---|---|---|
| Equipment size | Smallest (≤5 lbs) | Medium to large | Largest (100+ tons) |
| Pressure | Varies | High/very high | Low (vacuum) |
| Recovery level | 90%/80% or 4" Hg | 0 psig / 10" Hg | 25 mm Hg absolute |
| Compressor type | Hermetic | Various | Centrifugal |
| Primary concern | Trapped refrigerant in oil | Leak rates and repair | Air infiltration, tube failure |
| Safety device | N/A | PRV | Rupture disc (15 psig) |
| Special tool | Line tap valve | Push-pull machine | Purge unit, eddy current tester |
Test Your Knowledge
What is the recovery requirement for a Type I appliance with a non-functioning compressor?
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Test Your Knowledge
What is the required evacuation level for a Type III system (manufactured after 11/15/1993)?
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D
Test Your Knowledge
What are the three leak rate triggers in order from lowest to highest?
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Test Your Knowledge
Where does a Type III technician charge liquid refrigerant into a centrifugal chiller?
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D