What gets tested · Type II
The EPA 608 Type II section: high-pressure systems
If a refrigerant's saturation pressure at 104 °F is 45 psia or higher, work on the equipment it's in falls under EPA 608 Type II certification, unless that equipment is a small appliance or a motor-vehicle air conditioner (40 CFR 82.161(a)(1), eCFR as of October 5, 2026). That spans medium-, high- and very-high-pressure appliances, from a residential split system to a commercial walk-in cooler, and once you can place a refrigerant on the scale below, the pressure-class questions become a lookup.
Where Type II starts and stops
The pressure classes
Pressure classes by saturation pressure at 104 °F
| Class | Saturation pressure at 104 °F | Example refrigerants | Certification |
|---|---|---|---|
| Low | Below 45 psia | R-123, R-113, R-245fa | Type III |
| Medium | 45 to 170 psia | R-12, R-134a, R-114, R-124, R-500 | Type II |
| High | 170 to 355 psia | R-22, R-407A, R-407C, R-502 | Type II |
| Very high | Above 355 psia, or critical temperature below 104 °F | R-13, R-23, R-503, R-508A, R-508B | Type II |
Source: 40 CFR 82.152 definitions, eCFR as of October 5, 2026. Small appliances and motor-vehicle air conditioners are outside Type II whatever their pressure.
What the section covers
A field-charged split system isn't a small appliance, so household central air sits in Type II rather than Type I (40 CFR 82.152, eCFR as of October 5, 2026). Off-road vehicle air conditioning that meets the MVAC-like definition (open drive, 20 lb or less, not R-22) is the one overlap: it can be serviced with Type II or with Section 609 certification. Air conditioning in cars and trucks serviced for pay is Section 609 only. The two programs are compared on EPA 608 vs 609.
For Type II the test topics group the material into leak detection, leak repair requirements, recovery requirements, recovery techniques, refrigeration basics and safety (EPA test topics, checked October 7, 2026). Two of those carry enough rules to have their own pages here: leak detection and repair and required evacuation levels.
Two numbers worth carrying in
Absolute pressure equals gauge pressure plus 14.7 (psia = psig + 14.7), which is what you need to read a pressure-temperature chart. ESCO Institute, one of the EPA-approved programs, provides a PT chart during its exam (ESCO remote exam page, checked October 7, 2026); check what your own program allows.
System-dependent recovery equipment is barred on appliances holding more than 15 lb unless it's a permanently attached pump-out unit (40 CFR 82.156, eCFR as of October 5, 2026). On anything larger, the recovery machine has to bring its own pump.
The very-high-pressure corner
Very-high-pressure covers refrigerants above 355 psia at 104 °F and those whose critical temperature is below 104 °F, such as R-23 and R-508B in low-temperature cascade systems (40 CFR 82.152, eCFR as of October 5, 2026). They share the simplest row of the evacuation table: 0 inHg whatever the charge or equipment date.
Safety items specific to Type II
ASHRAE Standard 15, as the test topics summarize it, calls for an oxygen-deprivation sensor in equipment rooms, and a refrigerant sensor where R-123 is used. A large release in a closed machinery room displaces oxygen, often before anyone notices. The same topics state that hydrocarbons aren't approved as retrofits for these systems (EPA test topics, checked October 7, 2026).
Type II topics in depth
Pressure class first, then the rule
Before reading the options, note whether liquid or vapor is moving in the stem; recovery and charging answers depend on it.
0 right · 0 of 18 answered
Which of the following refrigerants is considered a high-pressure refrigerant requiring Type II certification?
Why each option is right or wrong
Answer: B. R-410A
- AR-123 is a low-pressure refrigerant used in chillers, which falls under Type III.
- BCorrect: R-410A is a high-pressure refrigerant (170–355 psia at 104°F), so it falls under Type II.
- CR-1233zd is a low-pressure chiller refrigerant, a Type III refrigerant.
- DR-11 is a low-pressure CFC used in centrifugal chillers, which is Type III work.
R-410A is classified as a high-pressure refrigerant that requires Type II certification due to its significantly higher operating pressures compared to traditional refrigerants.
What certification level is required to work on a rooftop package air conditioning unit containing R-410A?
Why each option is right or wrong
Answer: B. Type II certification
- ACore alone certifies no one to service equipment; it must be passed together with a Type.
- BCorrect: a rooftop package unit with R-410A is a high-pressure appliance that is not a small appliance, so it needs Type II.
- CType I covers only factory-sealed small appliances with 5 lb or less, not a rooftop package unit.
- DType III covers low-pressure appliances such as R-123 chillers, not R-410A units.
R-410A is a high-pressure refrigerant commonly used in rooftop package air conditioning units, requiring Type II certification for proper handling and servicing.
What is the correct order of operations when recovering refrigerant from a high-pressure system?
Why each option is right or wrong
Answer: A. Recover liquid first, then vapor
- ACorrect: liquid moves far faster than vapor, so pulling liquid first removes most of the charge quickly, and vapor recovery finishes the job.
- BRecovering only vapor works but is very slow on a large charge and leaves out the fastest step.
- CLiquid alone cannot reach the required evacuation level; the remaining vapor must also be recovered.
- DVapor first wastes time; the liquid is still sitting in the system, holding most of the charge.
The correct order is to recover liquid first, then vapor, to achieve required vacuum levels most efficiently and safely.
What precaution should be taken when recovering refrigerant from a high-pressure system in high ambient temperatures?
Why each option is right or wrong
Answer: C. Keep the recovery cylinders cool to prevent excessive pressure buildup
- AThere is no rule limiting recovery to nighttime; managing cylinder temperature is what matters.
- BHeat raises cylinder pressure, so high ambient temperatures do call for precautions.
- CCorrect: shade or cool the recovery cylinder, since a hot cylinder builds pressure, slows recovery and can open the relief valve.
- DNitrogen in a recovery cylinder is a non-condensable that raises its pressure, which is the opposite of what you want.
When recovering refrigerant in high ambient temperatures, recovery cylinders should be kept cool (using methods like shade, wet cloths, or fans) to prevent excessive pressure buildup that could trigger relief valves or create safety hazards.
What should be done if the system pressure rises after recovering refrigerant and isolating the recovery equipment?
Why each option is right or wrong
Answer: A. Perform additional recovery
- ACorrect: a pressure rise means refrigerant is still in the system, often coming out of the oil, so you must recover again before opening it.
- BOpening a system that is still releasing refrigerant would vent it; you have to recover more first.
- CA rise after isolation is a warning sign of remaining refrigerant, not normal behavior to ignore.
- DAdding nitrogen does not remove the refrigerant still in the system; it just mixes with it.
If system pressure rises after refrigerant recovery and isolation, additional recovery is required as this indicates refrigerant is still present in the system, possibly trapped in oil or components.
What is required when venting oil from a high-pressure refrigeration system?
Why each option is right or wrong
Answer: C. All refrigerant must be recovered from the oil first
- AThere is no 150°F rule; heating oil to 130°F before draining it is a Type III practice for low-pressure chillers.
- BOil holds dissolved refrigerant, so draining it without recovering first releases refrigerant.
- CCorrect: refrigerant dissolves in oil, so recover the refrigerant before draining the oil or it escapes into the air.
- DCarbon filters do not stop refrigerant from escaping; recovery does.
When venting oil from a high-pressure refrigeration system, all refrigerant must be recovered from the oil first to prevent refrigerant release to the atmosphere, as refrigerant dissolves in oil.
How should recovery equipment be connected to a high-pressure system for most efficient recovery?
Why each option is right or wrong
Answer: C. Connect to both high and low sides with large diameter hoses and minimal restrictions
- APicking a port by the highest reading does not give the fastest recovery; port location and hose size matter.
- BThe high side is where liquid is pulled, but connecting there alone leaves the low side to recover slowly.
- CCorrect: connecting to both sides with short, large-diameter hoses and minimal restrictions lets liquid and vapor come out at the same time, which is fastest.
- DLow-side-only recovery is the slowest option and is not needed to protect the recovery unit.
For most efficient recovery from a high-pressure system, recovery equipment should be connected to both high and low sides with large diameter hoses and minimal restrictions, as this allows liquid recovery from the high side and vapor from the low side simultaneously.
In the context of a cooling system, removing which component counts as a 'major repair' under EPA regulations?
Why each option is right or wrong
Answer: A. Condenser
- ACorrect: removing the condenser is a major repair under EPA rules, along with the compressor, evaporator or auxiliary heat-exchange coil.
- BInsulation is outside the refrigerant circuit, so removing it does not open the system.
- CA thermostat is an electrical control; replacing it does not open the refrigerant circuit.
- DFan blades are outside the refrigerant circuit, so replacing them is not a major repair.
According to the EPA, a 'major repair' includes any maintenance or service requiring the removal of key components such as the compressor, condenser, evaporator, or auxiliary heat exchanger coil.
Before engaging a recovery machine on a Type II system, which preliminary step is absolutely necessary to ensure proper operation and prevent contamination?
Why each option is right or wrong
Answer: A. Check and align valve positions
- ACorrect: check that the valves on the system, hoses, recovery unit and cylinder are in the right positions before starting, or the machine may run dead-headed, pull air or vent refrigerant.
- BReplacing the filter-drier is a repair step done after recovery, not before starting the recovery machine.
- CA deep vacuum is pulled after repairs; you cannot evacuate a system that still holds refrigerant before recovering it.
- DPressurizing with nitrogen before recovery would contaminate the refrigerant you are about to recover.
Technicians must verify valve positions and purge hoses before engaging the recovery machine to safely fully recover refrigerant with certified equipment and avoid venting.
Which sequence represents the correct procedural order for replacing a compressor on a high-pressure appliance to ensure compliance and prevent contamination?
Why each option is right or wrong
Answer: A. Isolate, recover, purge, remove, replace filter-drier, evacuate
- ACorrect: isolate the circuit, recover the charge, break the vacuum with nitrogen, remove the compressor, replace the filter-drier and then evacuate before charging.
- BEvacuating before replacing the filter-drier and purging afterward lets air and moisture back in, which defeats the evacuation.
- CPurging with nitrogen before recovering would push refrigerant out and contaminate it with nitrogen.
- DRecovering the whole charge before isolating the circuit means recovering more refrigerant than the repair needs; isolate first.
Isolate the circuit, recover the refrigerant, purge with nitrogen, remove the compressor, replace the filter-drier, and evacuate. Each of the other sequences puts a step out of order.
What is the preferred gas to use when leak testing a high-pressure system?
Why each option is right or wrong
Answer: C. Nitrogen
- AWrong: oxygen can explode when it meets compressor oil under pressure, so it is never used for leak testing.
- BWrong: helium is a specialty tracer gas, not the standard gas for pressurizing a high-pressure system for a leak test.
- CCorrect: dry nitrogen is inert, dry and non-flammable, which makes it the preferred gas for pressurizing a system for a leak test.
- DWrong: carbon dioxide is not the standard leak-test gas and can react with moisture to form acid.
Nitrogen is the preferred gas for leak testing high-pressure systems as it is inert, non-flammable, and does not contribute to ozone depletion.
What happens when high-pressure refrigerant passes through the metering device in a properly functioning system?
Why each option is right or wrong
Answer: C. Pressure drops and refrigerant begins to evaporate
- ASuperheating happens at the end of the evaporator and in the suction line, not as refrigerant passes the metering device.
- BThe metering device drops pressure; it does not raise it and cause condensation.
- CCorrect: the metering device drops the pressure, so the liquid starts boiling at a low temperature and can absorb heat in the evaporator.
- DTemperature falls across the metering device because the pressure drops.
When high-pressure refrigerant passes through the metering device, its pressure drops significantly, causing the refrigerant to begin evaporating and absorbing heat, which is the fundamental cooling process.
What is the primary purpose of the receiver in a high-pressure system?
Why each option is right or wrong
Answer: A. Store excess liquid refrigerant
- ACorrect: the receiver holds extra liquid refrigerant so the metering device gets a steady liquid supply as the load changes.
- BFiltering is done by the filter-drier, not the receiver.
- CCooling the refrigerant is the condenser's job.
- DCompression is done only by the compressor.
The receiver stores excess liquid refrigerant and ensures proper liquid feed to the expansion device during varying load conditions.
What effect will non-condensable gases in a refrigeration system have on its performance?
Why each option is right or wrong
Answer: B. High discharge pressure
- ANon-condensables make the system run poorly, not steadily.
- BCorrect: air and other non-condensables gather in the condenser, take up space and do not condense, so head pressure climbs.
- CNon-condensables reduce capacity and tend to warm things up; they do not make the refrigerant colder.
- DDischarge pressure goes up with non-condensables, not down.
Non-condensable gases, such as air, can accumulate in refrigeration systems and lead to high discharge pressure. This occurs because the gases do not condense and exit through the condenser, affecting system pressure and efficiency.
Which component of a high-pressure system is ideal for removing refrigerant during the recovery process?
Why each option is right or wrong
Answer: D. The liquid line service valve at the storage tank.
- AThe suction line holds vapor, so recovery there is slow.
- BThe discharge line carries hot vapor from the running compressor and is not where you pull liquid.
- CThere is no 'air intake valve' on the condenser's refrigerant circuit.
- DCorrect: the liquid line valve at the receiver (storage tank) is where you can pull liquid, which removes most of the charge fastest.
Recovering from the liquid line service valve nearest the receiver (storage tank) removes the refrigerant fastest, because liquid moves far more mass than vapor.
What is the proper sequence for charging a high-pressure system?
Why each option is right or wrong
Answer: A. Evacuate, break vacuum with vapor, complete with liquid
- ACorrect: evacuate first, break the vacuum with vapor so liquid doesn't flash and freeze, then finish with liquid through the liquid line.
- BWrong: charging only through the suction side is slow and skips the evacuation needed after the system was opened.
- CWrong: liquid alone into a deep vacuum flashes and can freeze components and moisture before pressure builds.
- DWrong: skipping evacuation leaves air and moisture in the system, which raises head pressure and forms acid.
Evacuate system, break vacuum with vapor refrigerant, then complete charging with liquid refrigerant through the liquid line.
What is the rationale behind using a liquid recovery with vapor assist method in high-pressure systems?
Why each option is right or wrong
Answer: D. It leverages both liquid and vapor recovery to speed up the removal process
- AKeeping the system compressor running is not the point; the method works with the recovery machine whether or not the system's compressor runs.
- BOil contamination is not what this method addresses; its purpose is speed.
- CTest gases have nothing to do with recovery method choice.
- DCorrect: pulling liquid first and then finishing with vapor recovery combines the speed of liquid recovery with the completeness of vapor recovery.
This method combines the advantages of liquid recovery's speed with vapor recovery's ability to remove remaining refrigerant rapidly, resulting in efficient overall recovery.
What type of pressure relief device is required on recovery cylinders used with high-pressure refrigerants?
Why each option is right or wrong
Answer: B. A DOT-approved pressure relief device
- AA manual valve depends on someone opening it; the cylinder needs an automatic relief device.
- BCorrect: recovery cylinders are DOT-approved containers fitted with a pressure relief device that opens automatically before the cylinder ruptures.
- CA color indicator does not relieve pressure, so it cannot prevent rupture.
- DAn alarm warns but does not release pressure; the requirement is a relief device.
Recovery cylinders used with high-pressure refrigerants must have a DOT-approved pressure relief device (such as a rupture disk or pressure relief valve) to prevent cylinder rupture if pressure becomes excessive due to overfilling or heat exposure.
More practice across all four sections: Practice test · Timed mock
Before you book Type II
Can you take Type II without Type I?
Yes. Each type test pairs Core with one type section, so Core plus Type II earns Type II on its own; Universal needs Core and all three types, in one sitting or by combining separate passes (40 CFR 82, Appendix D (a), eCFR as of October 5, 2026).
Is the Type II test open-book?
No. Type II, Type III and Universal tests are closed-book and proctored; only Type I allows a mail-in format (40 CFR 82, Appendix D (a), eCFR as of October 5, 2026). Details on whether the EPA 608 test is open book.
Is a heat pump Type I or Type II?
It depends on how it was built. A packaged terminal heat pump, charged and sealed at the factory, is listed as a small appliance and falls under Type I; a split-system heat pump charged in the field is Type II (40 CFR 82.152, eCFR as of October 5, 2026).
Does Type II certification replace a state HVAC license?
No. Section 608 is the federal refrigerant-handling requirement; separately, some states and localities require HVAC technicians to be licensed (BLS Occupational Outlook Handbook, checked October 7, 2026).