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EPA 608 Type II
Practice Test

Type II is the section that matters most for a typical HVAC career, because it covers the equipment most technicians touch every day: split systems and heat pumps using R-410A, legacy R-22 systems still in service, and commercial refrigeration. It is also the most technical section, with required evacuation levels that vary by charge size and equipment age, leak-repair thresholds that vary by appliance type, and the recovery and charging practice that goes with a system operating well above atmospheric pressure.

100
Questions
25
Per Attempt
70%
To Pass
Lifetime
Cert Validity
Practice
Take the Type II Practice Test
25 questions drawn at random from a bank of 100. Every answer comes with an explanation, and you can retake it as many times as you like.
Question 1 of 250 correct so far
System diagnostics and pressure

High head pressure with normal suction pressure most commonly indicates:

Scope
What EPA 608 Type II Covers
High-pressure and very high-pressure appliances — residential and commercial AC, heat pumps, and refrigeration.
High-pressure appliance definitions
9 practice questions in the bank below.
Required evacuation levels
13 practice questions in the bank below.
Leak repair thresholds and deadlines
16 practice questions in the bank below.
Recovery and recovery equipment
15 practice questions in the bank below.
Refrigerant charging
8 practice questions in the bank below.
System diagnostics and pressure
13 practice questions in the bank below.
Oils, moisture, and contamination
10 practice questions in the bank below.
Nitrogen pressure testing
7 practice questions in the bank below.
Safety
9 practice questions in the bank below.
Who needs this section
Most working HVAC technicians. Type II covers residential split systems, rooftop units, heat pumps, and commercial refrigeration.

Key Takeaways

The EPA 608 Type II exam is 25 multiple-choice questions and requires 70% to pass. It covers high-pressure and very high-pressure appliances — residential and commercial ac, heat pumps, and refrigeration. Certification never expires, and the exam is open-book.

  • Free practice bank: 100 questions, every answer explained
  • 25 questions per attempt, randomized · unlimited retakes
  • Core must be passed alongside any Type section
  • Exam cost is typically $20–$40 at an EPA-approved testing organization
Answer Key
All 100 Type II Questions Explained
The full bank with correct answers and the reasoning behind each one. Use it to study before you test, or to review after an attempt.

1. A high-pressure appliance is one that uses a refrigerant with a boiling point:

  1. Above 50°F at atmospheric pressure
  2. Between −50°F and 10°F at atmospheric pressure
  3. Below −50°F at atmospheric pressure
  4. Exactly 32°F at atmospheric pressure
Answer: B — Between −50°F and 10°F at atmospheric pressure
High-pressure refrigerants such as R-22, R-410A, and R-134a boil between roughly −50°F and 10°F at atmospheric pressure, which means the system operates above atmospheric pressure throughout. Below −50°F puts a refrigerant in the very-high-pressure category, and above 50°F makes it a low-pressure refrigerant.

2. For a high-pressure appliance with a charge of less than 200 pounds, manufactured after November 15, 1993, the required evacuation level before opening the system is:

  1. 0 inches of mercury
  2. 4 inches of mercury
  3. 10 inches of mercury
  4. 15 inches of mercury
Answer: C — 10 inches of mercury
Ten inches of mercury applies to post-1993 high-pressure appliances under 200 pounds; the requirement deepens to 15 inches at 200 pounds or more. Equipment manufactured before November 15, 1993 has a shallower table, which is why the question always tells you the manufacture date and the charge size.

3. For a high-pressure appliance with a charge of 200 pounds or more, manufactured after November 15, 1993, the required evacuation level is:

  1. 4 inches of mercury
  2. 10 inches of mercury
  3. 15 inches of mercury
  4. 25 mm of mercury absolute
Answer: C — 15 inches of mercury
Fifteen inches of mercury is the deeper requirement that comes with the larger charge, on the reasoning that more refrigerant left behind means a larger release. The 25 mm Hg absolute figure belongs to low-pressure appliances and is a Type III answer.

4. Very high-pressure appliances, such as those using R-13 or R-503, must be evacuated to:

  1. 25 mm of mercury absolute
  2. 10 inches of mercury
  3. 15 inches of mercury
  4. 0 psig
Answer: D — 0 psig
Very high-pressure refrigerants cannot practically be pulled into a vacuum with standard recovery equipment, so the requirement is simply to bring the system down to atmospheric pressure — 0 psig. Trying to apply the high-pressure table here is a common exam trap.

5. Under the leak repair requirements, which appliances are covered?

  1. Appliances with a full charge of 50 pounds or more
  2. All appliances regardless of charge
  3. Appliances with a full charge of 100 pounds or more
  4. Only commercial refrigeration systems
Answer: A — Appliances with a full charge of 50 pounds or more
Fifty pounds of full charge is the threshold that pulls an appliance into the leak repair program — leak-rate calculation, repair, and verification testing. Below that, the venting prohibition and recovery rules still apply, but the formal repair-and-verify process does not.

6. For comfort cooling appliances subject to the leak repair requirements, the annual leak rate that triggers repair is:

  1. 5%
  2. 10%
  3. 20%
  4. 30%
Answer: B — 10%
The 2016 rule set three thresholds effective January 1, 2019: 10% for comfort cooling and other appliances, 20% for commercial refrigeration, and 30% for industrial process refrigeration. They replaced the older 15%, 35%, and 35% figures, so a study guide printed before 2019 may show the wrong numbers.

7. The trigger leak rate for commercial refrigeration appliances is:

  1. 10%
  2. 20%
  3. 30%
  4. 35%
Answer: B — 20%
Commercial refrigeration sits at 20% under the current thresholds, between comfort cooling at 10% and industrial process refrigeration at 30%. Grouping them from lowest tolerance to highest — comfort cooling, commercial refrigeration, industrial process — is the easiest way to keep them straight.

8. Once a covered appliance is found to exceed its trigger leak rate, repairs must generally be completed within:

  1. 7 days
  2. 30 days
  3. 90 days
  4. One year
Answer: B — 30 days
Thirty days is the repair window, followed by initial and follow-up verification tests to confirm the repair held. If repair is not feasible, the owner must instead develop a retrofit or retirement plan within 30 days and complete it within one year — the one-year figure belongs to that path, not to the repair itself.

9. The fastest method of removing a large refrigerant charge from a system is:

  1. Passive recovery with the compressor running
  2. Vapor recovery through the low side
  3. Push-pull liquid recovery
  4. Recovering through a filter-drier
Answer: C — Push-pull liquid recovery
Push-pull uses the recovery machine to pull vapor from the cylinder and push liquid from the system, moving the charge as a liquid column. It requires enough charge to justify the setup — typically 10 to 15 pounds or more — and you finish with conventional vapor recovery to clear the remainder.

10. Recovery goes unusually slowly on a hot day. The most effective corrective action is to:

  1. Warm the recovery cylinder
  2. Add nitrogen to the system to push refrigerant out
  3. Reduce the hose diameter
  4. Cool the recovery cylinder, for example in an ice bath
Answer: D — Cool the recovery cylinder, for example in an ice bath
Recovery is driven by the pressure difference between the system and the cylinder, so a hot cylinder fights you. Cooling it lowers cylinder pressure and speeds transfer. Adding nitrogen contaminates the recovered refrigerant with a non-condensable and can make it unreclaimable.

11. Polyolester (POE) oil used with R-410A requires special handling because it:

  1. Absorbs moisture from the air rapidly and is difficult to dry once wet
  2. Cannot be used with copper tubing
  3. Is flammable at room temperature
  4. Breaks down above 100°F
Answer: A — Absorbs moisture from the air rapidly and is difficult to dry once wet
POE is hygroscopic — it pulls moisture out of the air quickly and holds it chemically, where mineral oil would let it settle out. That is why POE containers stay capped, why lines are kept sealed during installation, and why moisture in an R-410A system leads to acid formation faster than in an older R-22 system.

12. R-410A operates at pressures roughly how much higher than R-22 at the same conditions?

  1. About 10% higher
  2. About 50% to 60% higher
  3. About the same
  4. About 200% higher
Answer: B — About 50% to 60% higher
R-410A runs roughly 50 to 60 percent higher than R-22, which is why it requires gauges, hoses, and recovery equipment rated for it and why R-410A service cylinders are rose-colored and built to a higher pressure rating. Using R-22-rated equipment on R-410A is a rupture hazard, not just a measurement error.

13. R-410A must be charged into a system as a liquid because it is:

  1. Too dense to charge as a vapor
  2. An azeotropic blend that separates when charged as vapor
  3. A near-azeotropic (zeotropic) blend whose components would fractionate if charged as vapor
  4. Corrosive in the vapor phase
Answer: C — A near-azeotropic (zeotropic) blend whose components would fractionate if charged as vapor
Blends with components of different boiling points fractionate when vapor is drawn off the cylinder, so the refrigerant entering the system no longer matches the blend on the label. Charging liquid — throttled through the manifold into the suction line, never liquid-slugged into a running compressor — keeps the composition correct.

14. On a system with a fixed-orifice metering device, the technician charges by:

  1. Subcooling
  2. Discharge line temperature only
  3. Sight glass clarity only
  4. Superheat
Answer: D — Superheat
Fixed-orifice systems are charged by superheat, because the orifice does not control evaporator superheat and it varies with charge. TXV and EEV systems are charged by subcooling instead, since the valve holds superheat roughly constant and subcooling becomes the meaningful indicator of charge.

15. High head pressure combined with high subcooling most commonly indicates:

  1. An overcharged system or restricted condenser airflow
  2. A failed compressor valve
  3. An undercharged system
  4. A plugged metering device
Answer: A — An overcharged system or restricted condenser airflow
Excess refrigerant backs up in the condenser, increasing both the pressure and the amount of liquid subcooled below saturation. Restricted condenser airflow produces a similar picture. An undercharge would show the opposite — low subcooling with low head pressure.

16. When brazing refrigerant lines, dry nitrogen should be flowed through the tubing in order to:

  1. Cool the joint faster
  2. Prevent cupric oxide scale from forming inside the tubing
  3. Improve solder adhesion
  4. Satisfy an EPA requirement
Answer: B — Prevent cupric oxide scale from forming inside the tubing
Heating copper in the presence of oxygen forms a black flaky oxide inside the tube that later breaks loose and plugs metering devices and filter-driers. A low-flow nitrogen purge displaces the oxygen so the interior stays clean. It is a best practice enforced by manufacturers, not an EPA rule.

17. After a compressor burnout, refrigerant recovered from the system should be:

  1. Mixed with virgin refrigerant to dilute the acid
  2. Recycled on site and returned to the same system
  3. Kept separate and sent for reclamation or disposal, because it is acid-contaminated
  4. Vented, since it is contaminated
Answer: C — Kept separate and sent for reclamation or disposal, because it is acid-contaminated
Burnout refrigerant carries acid and combustion byproducts that on-site recycling will not remove, and returning it would destroy the replacement compressor. Recover it into a dedicated cylinder, label it, and send it for reclamation or destruction. Venting it is a violation regardless of its condition.

18. A suction-line filter-drier installed after a burnout should be:

  1. Left in place permanently
  2. Installed backwards to trap debris
  3. Installed in the liquid line instead
  4. Checked for pressure drop and typically removed or replaced after the system has run and cleaned up
Answer: D — Checked for pressure drop and typically removed or replaced after the system has run and cleaned up
A burnout cleanup drier collects acid and debris and will develop pressure drop as it loads up. Monitor it across the first hours of operation and replace or remove it once the system is clean, or the restriction it creates will starve the compressor of suction pressure.

19. The maximum pressure that may be applied when leak-testing a system with nitrogen is determined by:

  1. The lowest-rated component in the system, per the manufacturer's specification
  2. A fixed 150 psig limit set by EPA
  3. The nitrogen cylinder pressure
  4. The refrigerant's critical pressure
Answer: A — The lowest-rated component in the system, per the manufacturer's specification
The weakest component sets the ceiling — often the low-side design pressure or a factory-installed accessory. A regulated nitrogen source is mandatory because full cylinder pressure exceeds 2,000 psi and will burst evaporator tubing instantly. EPA sets no nitrogen test pressure; the manufacturer does.

20. A technician must reach the required evacuation level and then:

  1. Open the system immediately
  2. Verify the vacuum holds with the recovery equipment isolated, confirming the level was actually achieved
  3. Recharge the system to test for leaks
  4. Purge with nitrogen before opening
Answer: B — Verify the vacuum holds with the recovery equipment isolated, confirming the level was actually achieved
A reading taken while the machine runs can reflect the machine, not the system. Isolating and watching whether the level holds is what proves the refrigerant is actually out. If pressure climbs, refrigerant is still boiling out of the oil or the system is drawing in through a leak.

21. Which of these appliances falls under Type II certification?

  1. A household refrigerator with a 2-pound charge
  2. A 500-ton centrifugal chiller using R-123
  3. A rooftop packaged unit using R-410A
  4. A window air conditioner
Answer: C — A rooftop packaged unit using R-410A
Type II covers high-pressure equipment — rooftop units, split systems, heat pumps, and commercial refrigeration. The refrigerator and window unit are Type I small appliances, and an R-123 centrifugal chiller is a low-pressure appliance requiring Type III.

22. Adding R-22 to a system that was designed for R-410A would:

  1. Work acceptably as long as the charge weight is correct
  2. Be permitted if the system is later reclaimed
  3. Improve efficiency at low ambient temperatures
  4. Be a violation of the rule and would damage the system, since refrigerants and their oils are not interchangeable
Answer: D — Be a violation of the rule and would damage the system, since refrigerants and their oils are not interchangeable
Mixing refrigerants makes the resulting charge unreclaimable and creates unpredictable pressures, and the oils are incompatible — R-410A systems use POE, not mineral oil. Substituting a refrigerant outside the manufacturer's and EPA's approved use for that equipment is both a technical failure and a compliance problem.

23. Non-condensables in a high-pressure system are best confirmed by:

  1. Comparing head pressure to the saturation pressure of the refrigerant at the temperature of the liquid in the condenser after the system has been off and equalized
  2. Listening to the compressor
  3. Measuring superheat only
  4. Weighing the charge
Answer: A — Comparing head pressure to the saturation pressure of the refrigerant at the temperature of the liquid in the condenser after the system has been off and equalized
With the system off and at ambient, pressure should match the refrigerant's saturation pressure at that temperature. A reading meaningfully above it means something in the system is not condensing — air. The fix is recovery, evacuation, and recharge, not simply bleeding the head pressure off, which would be venting.

24. Refrigerant recovered from a high-pressure appliance may be returned to that same system without reclamation if:

  1. It came from a burnout
  2. It remains with the same owner and is recycled or simply reused after service
  3. It has been mixed with a different refrigerant
  4. It is transferred to a new owner
Answer: B — It remains with the same owner and is recycled or simply reused after service
Refrigerant staying with the same owner may be recovered and returned without going to a reclaimer. Change of ownership requires reclamation to AHRI 700, mixed refrigerant is not reusable, and burnout refrigerant should not go back into a system regardless of ownership.

25. Before working on a rooftop unit, the most important electrical safety step is to:

  1. Turn the thermostat to off
  2. Wear cotton gloves
  3. Lock out and tag out the disconnect and verify with a meter that the circuit is de-energized
  4. Remove the condenser fan
Answer: C — Lock out and tag out the disconnect and verify with a meter that the circuit is de-energized
A thermostat is a control, not a disconnect — the unit can energize from a call for cooling, a time clock, or a building automation system. Lock out, tag out, and verify with a meter, and remember that capacitors hold a dangerous charge after power is removed.

26. The leak rate for a covered appliance is calculated on:

  1. A per-service-call basis
  2. The number of leaks found
  3. The total refrigerant purchased by the company
  4. An annualized basis, as a percentage of the appliance's full charge
Answer: D — An annualized basis, as a percentage of the appliance's full charge
The rule annualizes the amount added over the period between services and expresses it as a percentage of full charge, so a large system tolerates more absolute leakage than a small one before hitting the same threshold. Accurate full-charge documentation is therefore a compliance requirement, not just good practice.

27. A liquid-line filter-drier should be replaced whenever the system is opened because:

  1. A drier that has already adsorbed moisture will release it back into the system and cannot protect the new charge
  2. Driers expire after 12 months
  3. EPA requires a new drier after every recovery
  4. The old drier will restrict liquid flow immediately
Answer: A — A drier that has already adsorbed moisture will release it back into the system and cannot protect the new charge
Desiccant is a finite resource: once loaded, it can desorb moisture back into the refrigerant, especially as temperature rises. Replacing the drier on every system opening is manufacturer practice, not an EPA rule, and it is the cheapest insurance against acid formation there is.

28. Low suction pressure with high superheat on a TXV system most commonly indicates:

  1. An overcharge
  2. A restriction or an undercharge starving the evaporator
  3. A failed condenser fan
  4. Excess subcooling
Answer: B — A restriction or an undercharge starving the evaporator
Both symptoms point at not enough refrigerant reaching the evaporator, whether because the charge is low or because a drier, valve, or screen is restricting flow. Checking subcooling separates the two: low subcooling suggests undercharge, while high subcooling with a temperature drop across a component points to a restriction.

29. Recovery equipment used on a system containing R-410A must be:

  1. Fitted with a halide torch
  2. Any recovery machine, since all refrigerants recover the same way
  3. Rated for the pressures R-410A produces, with hoses and gauges rated to match
  4. Operated only above 90°F ambient
Answer: C — Rated for the pressures R-410A produces, with hoses and gauges rated to match
R-410A operates well above R-22 pressures, so machines, hoses, gauges, and recovery cylinders must all carry the higher rating. Using R-22-era equipment is a rupture hazard rather than a measurement inconvenience, and cylinders in particular are rated by service pressure.

30. A recovery cylinder is being filled and its pressure rises sharply while weight barely changes. The most likely explanation is:

  1. The recovery machine is running too slowly
  2. The scale is miscalibrated
  3. The system is fully recovered
  4. The cylinder contains non-condensables or a different refrigerant
Answer: D — The cylinder contains non-condensables or a different refrigerant
Pressure rising without corresponding weight means something in the cylinder is not condensing — air, or a refrigerant with different saturation properties. Stop and investigate: continuing risks tripping the high-pressure cutout and, worse, producing a mixed cylinder that cannot be reclaimed.

31. A high-pressure appliance is defined by a refrigerant with a boiling point between what temperatures at atmospheric pressure?

  1. Above 50°F
  2. Below -100°C
  3. Between -50°C and 10°C
  4. Above 100°C
Answer: C — Between -50°C and 10°C
High-pressure refrigerants boil between about -50°C and 10°C at atmospheric pressure — the band that covers R-22, R-410A, R-134a, and R-404A. Low-pressure refrigerants such as R-11 and R-123 boil above 10°C, which is what puts them under Type III.

32. Which refrigerant would place an appliance under Type III rather than Type II?

  1. R-410A
  2. R-134a
  3. R-123
  4. R-404A
Answer: C — R-123
R-123 is a low-pressure refrigerant that boils above 10°C at atmospheric pressure, so its equipment operates in a vacuum on the low side and falls under Type III. The other three are high-pressure refrigerants covered by Type II.

33. Type II certification covers which equipment?

  1. Only chillers
  2. Only appliances under 5 pounds
  3. Only automobile air conditioning
  4. High-pressure and very high-pressure appliances above the small-appliance threshold
Answer: D — High-pressure and very high-pressure appliances above the small-appliance threshold
Type II covers high-pressure and very high-pressure equipment that exceeds the small-appliance definition — supermarket racks, rooftop units, residential split systems, and process refrigeration. Motor-vehicle air conditioning is certified separately under Section 609.

34. A residential split-system heat pump with a 9-pound charge requires which certification?

  1. Type II
  2. Type I
  3. Type III
  4. None
Answer: A — Type II
It is field-charged, not factory-sealed, and it holds well over five pounds of a high-pressure refrigerant, so Type I does not reach it. Type II is the correct certification for high-pressure equipment of this kind.

35. What distinguishes a "very high-pressure appliance" from a high-pressure one?

  1. It holds more refrigerant
  2. It runs on three-phase power
  3. It uses a refrigerant boiling below -50°C at atmospheric pressure, such as R-13 or R-503
  4. It is always industrial
Answer: C — It uses a refrigerant boiling below -50°C at atmospheric pressure, such as R-13 or R-503
Very high-pressure appliances use refrigerants that boil below -50°C — R-13, R-503, R-23 and similar, typically in cascade low-temperature systems. They are grouped with Type II, but the rule sets no evacuation requirement for them because recovery equipment cannot pull the required vacuum.

36. Is a supermarket refrigeration rack a Type II appliance?

  1. No, it is Type I
  2. Only if it uses R-22
  3. No, it is Type III
  4. Yes — it is high-pressure equipment far above the small-appliance charge
Answer: D — Yes — it is high-pressure equipment far above the small-appliance charge
A supermarket rack holds hundreds or thousands of pounds of high-pressure refrigerant in a field-assembled system, which is Type II territory. Its size also puts it firmly inside the leak repair regime.

37. A high-pressure appliance containing more than 200 pounds of refrigerant, being opened for major service with recovery equipment manufactured on or after November 15, 1993, must be evacuated to what level?

  1. 0 inches Hg vacuum
  2. 4 inches Hg vacuum
  3. 10 inches Hg vacuum
  4. 15 inches Hg vacuum
Answer: C — 10 inches Hg vacuum
The required level for appliances above 200 pounds is 10 inches of mercury vacuum with post-November 1993 equipment. The tiering runs 0, 4, and 10 inches of mercury for charges under 200 pounds, 200 pounds and under, and above 200 pounds respectively — memorising the brackets is most of this topic.

38. A high-pressure appliance with a charge of less than 200 pounds, opened for major service using post-November 1993 equipment, must be evacuated to:

  1. 4 inches Hg vacuum
  2. 0 inches Hg vacuum
  3. 10 inches Hg vacuum
  4. 25 inches Hg vacuum
Answer: A — 4 inches Hg vacuum
Four inches of mercury vacuum applies to high-pressure appliances holding less than 200 pounds when the recovery equipment was manufactured on or after November 15, 1993. Equipment made before that date is held to 0 inches of mercury for the same appliance.

39. Using recovery equipment manufactured before November 15, 1993 on a high-pressure appliance with under 200 pounds of charge, the required evacuation level is:

  1. 0 inches Hg vacuum
  2. 4 inches Hg vacuum
  3. 10 inches Hg vacuum
  4. 15 inches Hg vacuum
Answer: A — 0 inches Hg vacuum
Pre-November 1993 equipment is held to 0 inches of mercury — atmospheric pressure — on high-pressure appliances under 200 pounds. The older machines simply could not be expected to pull a vacuum, so the rule set the requirement at removing the charge down to atmospheric.

40. When is no evacuation level required before opening a high-pressure appliance?

  1. Never
  2. Only on weekends
  3. When the appliance is a very high-pressure appliance, or when the work is a minor repair or a leak test that does not require major component removal
  4. Only above 500 pounds
Answer: C — When the appliance is a very high-pressure appliance, or when the work is a minor repair or a leak test that does not require major component removal
The rule exempts very high-pressure appliances, and it distinguishes major service from minor repairs and leak testing. A repair that does not involve removing a major component can follow the reduced requirements rather than a full evacuation.

41. What counts as "major maintenance, service, or repair" triggering full evacuation?

  1. Changing a filter
  2. Cleaning a coil
  3. Checking superheat
  4. Removal of the compressor, condenser, evaporator, or auxiliary heat exchanger coil
Answer: D — Removal of the compressor, condenser, evaporator, or auxiliary heat exchanger coil
The rule names the major components explicitly: compressor, condenser, evaporator, and auxiliary heat exchanger coil. Removing any of them is major service. Work that leaves all four in place falls under the lighter requirements for minor repairs.

42. After an evacuation to the required level, the system must be:

  1. Isolated and the vacuum verified to hold before the work proceeds
  2. Immediately recharged
  3. Pressurised with oxygen
  4. Left open indefinitely
Answer: A — Isolated and the vacuum verified to hold before the work proceeds
Valving off and watching the vacuum confirms you actually reached and held the level rather than reading a momentary number. A vacuum that climbs back means either remaining refrigerant boiling off or air leaking in, and both change what you do next.

43. Why does the required evacuation level increase with appliance charge size?

  1. Larger systems are newer
  2. It does not increase
  3. A larger charge means more residual refrigerant left behind at any given pressure, so a deeper vacuum is needed to limit emissions
  4. To slow technicians down
Answer: C — A larger charge means more residual refrigerant left behind at any given pressure, so a deeper vacuum is needed to limit emissions
The same residual pressure in a larger volume leaves proportionally more refrigerant in the system to escape when it is opened. Requiring a deeper vacuum on bigger charges keeps the absolute quantity released roughly in check.

44. What is the leak rate threshold that triggers repair requirements for a commercial refrigeration appliance with more than 50 pounds of charge?

  1. 10% per year
  2. 20% per year
  3. 30% per year
  4. 35% per year
Answer: C — 30% per year
Commercial refrigeration carries a 30% annual leak rate trigger. Industrial process refrigeration is 30% as well, while comfort cooling and all other appliance types sit at 10%. These thresholds took effect January 1, 2019.

45. What is the leak rate threshold for a comfort-cooling appliance with more than 50 pounds of charge?

  1. 5% per year
  2. 35% per year
  3. 15% per year
  4. 10% per year
Answer: D — 10% per year
Comfort cooling and the catch-all "other appliances" category trigger at 10% annually. Commercial refrigeration and industrial process refrigeration both sit at 30%, which is the pairing candidates most often reverse.

46. What is the leak rate threshold for industrial process refrigeration over 50 pounds?

  1. 10%
  2. 20%
  3. 30%
  4. 50%
Answer: C — 30%
Industrial process refrigeration triggers at 30% per year, the same figure as commercial refrigeration. Comfort cooling is the outlier at 10%.

47. Once a leak rate exceeding the threshold is found, how long does the owner have to repair the leak?

  1. 30 days
  2. 10 days
  3. 90 days
  4. 1 year
Answer: A — 30 days
Repairs must be completed within 30 days of discovering that the appliance is leaking above its threshold. Extensions exist for specific circumstances such as industrial process shutdowns and parts that must be ordered from abroad, but 30 days is the baseline.

48. After repairs, what must be done to demonstrate the leak was fixed?

  1. Nothing
  2. Only a visual inspection
  3. An initial verification test and a follow-up verification test
  4. Wait one year
Answer: C — An initial verification test and a follow-up verification test
Two tests are required: an initial verification before the appliance is returned to full charge and operation, and a follow-up verification once it is operating at normal conditions. One test alone does not close out the repair.

49. The leak repair requirements apply to appliances containing how much refrigerant?

  1. Any amount
  2. More than 5 pounds
  3. More than 50 pounds
  4. More than 200 pounds
Answer: C — More than 50 pounds
Fifty pounds is the threshold at which the leak-rate calculation, repair deadlines, and verification testing attach. Appliances at or below it — including all small appliances — are outside the regime, though the venting prohibition still covers them.

50. What must an owner do if repairs cannot bring the appliance below its leak rate threshold?

  1. Continue operating indefinitely
  2. Nothing
  3. Vent the remaining charge
  4. Develop a retrofit or retirement plan within 30 days and complete it within one year
Answer: D — Develop a retrofit or retirement plan within 30 days and complete it within one year
When repair fails, the rule shifts to a plan: a retrofit or retirement plan within 30 days of the failed verification, to be carried out within a year. The intent is that a chronically leaking appliance is eventually removed rather than topped up forever.

51. How is the annualized leak rate calculated?

  1. Pounds of refrigerant added, divided by full charge, annualized over the period since the last addition
  2. Pounds lost divided by system age
  3. Number of leaks found per year
  4. Hours of runtime per leak
Answer: A — Pounds of refrigerant added, divided by full charge, annualized over the period since the last addition
The rolling average method takes the refrigerant added, divides by the appliance\u2019s full charge, and annualizes over the time since the previous addition. That is why accurate servicing records matter — without dates and quantities the rate cannot be computed.

52. Which appliances must have leak inspections at intervals set by the rule?

  1. All appliances
  2. Only small appliances
  3. Appliances with more than 500 pounds of refrigerant that have exceeded the threshold, among others on a charge-size schedule
  4. None
Answer: C — Appliances with more than 500 pounds of refrigerant that have exceeded the threshold, among others on a charge-size schedule
Inspection frequency scales with charge: appliances over 500 pounds that have exceeded their threshold face quarterly inspections, while those between 50 and 500 pounds are annual. Automatic leak detection can substitute for the inspections.

53. Recovery equipment used on high-pressure appliances must be certified to meet what?

  1. AHRI 700 purity
  2. ASHRAE 34
  3. DOT 4BA
  4. The applicable EPA recovery efficiency requirements, verified by an approved laboratory
Answer: D — The applicable EPA recovery efficiency requirements, verified by an approved laboratory
An EPA-approved laboratory certifies the machine against the recovery efficiency requirements for its class of equipment. AHRI 700 is refrigerant purity after reclamation, ASHRAE 34 is the safety classification scheme, and DOT 4BA is a cylinder specification.

54. What is the benefit of recovering liquid refrigerant before vapour on a large high-pressure system?

  1. Liquid carries far more mass per minute, so the bulk of the charge comes out much faster
  2. It is required by rule
  3. It prevents leaks
  4. It cleans the oil
Answer: A — Liquid carries far more mass per minute, so the bulk of the charge comes out much faster
Liquid is hundreds of times denser than vapour at the same conditions, so push-pull or liquid recovery clears most of a large charge in a fraction of the time. The remaining vapour is then recovered conventionally.

55. What is the "push-pull" recovery method used for?

  1. Small appliances only
  2. Charging a system
  3. Moving large liquid charges by pushing with vapour pressure on one side and pulling with the recovery machine on the other
  4. Leak detection
Answer: C — Moving large liquid charges by pushing with vapour pressure on one side and pulling with the recovery machine on the other
Push-pull uses the recovery machine to raise pressure on the appliance\u2019s vapour side while drawing from the recovery cylinder, creating a liquid flow into the cylinder. It is efficient on large charges but needs enough liquid to establish flow, so it is not used on small systems.

56. Why should recovery hoses be as short and as large in diameter as practical?

  1. To save money
  2. To prevent frostbite
  3. To meet DOT rules
  4. To reduce pressure drop, which otherwise throttles recovery throughput
Answer: D — To reduce pressure drop, which otherwise throttles recovery throughput
Every foot of hose and every reduction in bore costs pressure differential, which is the only thing moving refrigerant. Short, wide hoses are the cheapest speed improvement available on a long recovery.

57. What condition indicates the recovery cylinder is full and must be changed?

  1. It reaches 80% of rated capacity by weight on the scale
  2. The gauge reads zero
  3. The hose gets cold
  4. One hour has passed
Answer: A — It reaches 80% of rated capacity by weight on the scale
The 80% by weight limit is read on a scale, using the tare weight stamped on the cylinder collar. A pressure gauge cannot tell you the fill level, and relying on one is how cylinders end up hydraulically full.

58. A recovery machine slows dramatically near the end of a recovery. The most likely cause is:

  1. A faulty scale
  2. Too much oil
  3. The pressure differential shrinking as the appliance approaches the cylinder pressure
  4. Cold weather only
Answer: C — The pressure differential shrinking as the appliance approaches the cylinder pressure
As the appliance empties, its pressure falls toward the cylinder pressure and the differential driving the transfer collapses. Chilling the cylinder restores some differential, which is why technicians ice the cylinder on the last stretch of a long recovery.

59. Refrigerant recovered from a customer\u2019s system and intended for sale to another party must first be:

  1. Filtered on site
  2. Mixed with virgin refrigerant
  3. Weighed only
  4. Reclaimed to AHRI 700 by an EPA-certified reclaimer
Answer: D — Reclaimed to AHRI 700 by an EPA-certified reclaimer
Once refrigerant changes ownership it must be reclaimed to AHRI 700 specification and verified by chemical analysis, and only an EPA-certified reclaimer may do that. On-site recycling only qualifies refrigerant to go back into the same owner\u2019s equipment.

60. Why is a zeotropic blend such as R-407C charged as a liquid?

  1. Vapour charging fractionates the blend and changes the composition of both the charge and the cylinder contents
  2. It charges faster
  3. It is required by DOT
  4. To avoid frostbite
Answer: A — Vapour charging fractionates the blend and changes the composition of both the charge and the cylinder contents
The components boil at different temperatures, so pulling vapour takes the more volatile component preferentially. Liquid charging preserves the proportions. Where liquid must enter the suction side, a metering device throttles it so the compressor is not slugged.

61. What is the risk of charging liquid refrigerant directly into the suction line without metering?

  1. Nothing
  2. Overheating the condenser
  3. Liquid slugging the compressor, which can break valves or connecting rods
  4. Loss of certification
Answer: C — Liquid slugging the compressor, which can break valves or connecting rods
Compressors are built to compress vapour, and liquid is effectively incompressible. A slug of liquid arriving at the cylinder can break reed valves or bend a rod. Metering the liquid through a restrictor lets it flash to vapour before it reaches the compressor.

62. Charging by weight requires knowing:

  1. The ambient temperature only
  2. The cylinder pressure
  3. The refrigerant colour
  4. The manufacturer\u2019s specified charge for the system, including any line-length adjustment
Answer: D — The manufacturer\u2019s specified charge for the system, including any line-length adjustment
Weighing in the charge is the most accurate method when the nameplate figure is known and the line set is accounted for — long line sets need an added allowance. Without the specified charge, weight alone tells you nothing about whether the system is correct.

63. Superheat charging is typically used on systems with what metering device?

  1. Fixed orifice or capillary tube
  2. Thermostatic expansion valve
  3. Electronic expansion valve only
  4. None
Answer: A — Fixed orifice or capillary tube
A fixed-orifice system does not control superheat itself, so measured superheat reflects the charge and the technique works. A TXV holds superheat roughly constant by design, so subcooling is the meaningful charging measurement there.

64. Subcooling charging is the appropriate method on which systems?

  1. Capillary-tube systems
  2. Only heat pumps in heating mode
  3. TXV or EEV systems
  4. Only R-22 systems
Answer: C — TXV or EEV systems
Because a TXV or EEV actively maintains superheat, superheat readings barely move with charge. Subcooling at the condenser outlet does respond to charge, so it is the measurement used on those systems.

65. High head pressure with normal suction pressure most commonly indicates:

  1. Low charge
  2. An oversized metering device
  3. A failed compressor valve
  4. A condenser problem — dirty coil, failed fan, or restricted airflow — or non-condensables
Answer: D — A condenser problem — dirty coil, failed fan, or restricted airflow — or non-condensables
The condenser rejects heat; when it cannot, head pressure climbs while the low side stays close to normal. Dirty coils, a dead condenser fan, recirculating air, or non-condensable gases in the system all produce this signature.

66. Low suction pressure with high superheat suggests:

  1. Undercharge or a restriction in the liquid line or metering device
  2. Overcharge
  3. Dirty condenser
  4. Too much airflow
Answer: A — Undercharge or a restriction in the liquid line or metering device
Both an undercharge and a restriction starve the evaporator, so the coil runs dry and superheat climbs while suction pressure falls. Subcooling separates them: low subcooling points to undercharge, high subcooling points to a restriction downstream of the condenser.

67. The presence of non-condensable gases such as air in a system causes:

  1. Lower head pressure
  2. Lower superheat
  3. Head pressure higher than the condensing temperature alone would explain
  4. Reduced oil return
Answer: C — Head pressure higher than the condensing temperature alone would explain
Air occupies condenser volume and adds its own partial pressure, so the head pressure reads higher than the saturation pressure corresponding to the actual condensing temperature. Comparing measured head pressure against condensing temperature is the standard way to detect it.

68. How are non-condensables usually removed from a high-pressure system?

  1. By venting the top of the condenser to atmosphere
  2. By adding more refrigerant
  3. With a purge unit
  4. By recovering the charge and evacuating the system properly before recharging
Answer: D — By recovering the charge and evacuating the system properly before recharging
Venting the condenser would release refrigerant along with the air and is a violation. The correct route is recovery, a proper deep evacuation to remove the non-condensables and moisture, and a fresh charge. Purge units belong to low-pressure Type III equipment.

69. What does high subcooling with low suction pressure typically indicate?

  1. A restriction in the liquid line or metering device
  2. Undercharge
  3. A dirty evaporator
  4. Normal operation
Answer: A — A restriction in the liquid line or metering device
Refrigerant backing up in the condenser raises subcooling, while the starved evaporator drops suction pressure — the classic restriction signature. An undercharge would show low subcooling instead, which is how the two are told apart.

70. A compressor that runs but produces little pressure differential likely has:

  1. A dirty condenser
  2. Too much charge
  3. Failed valves or internal bypass
  4. A bad thermostat
Answer: C — Failed valves or internal bypass
When the compressor turns but cannot build a differential, the usual cause is internal leakage — broken or leaking reed valves, or a worn scroll. A dirty condenser would raise head pressure, not collapse the differential.

71. Why must POE oil systems be kept closed as much as possible during service?

  1. POE is flammable
  2. POE is toxic
  3. POE evaporates
  4. POE is highly hygroscopic and absorbs atmospheric moisture rapidly
Answer: D — POE is highly hygroscopic and absorbs atmospheric moisture rapidly
Polyolester oil pulls moisture out of the air far faster than the mineral oil it replaced, and the absorbed water forms acids in service. Keeping the system sealed, minimising open time, and using fresh oil from a sealed container are the practical controls.

72. Which oil is normally used with R-410A?

  1. Mineral oil
  2. Polyolester (POE)
  3. Alkylbenzene
  4. Vegetable oil
Answer: B — Polyolester (POE)
HFC refrigerants such as R-410A are not miscible with mineral oil, so the oil will not return to the compressor. POE is the standard pairing. Mineral oil suits CFC and HCFC systems, and alkylbenzene is used with some HCFC and transitional blends.

73. What does an acid test on system oil indicate?

  1. Whether moisture and heat have degraded the oil, signalling contamination or an impending or past burnout
  2. The refrigerant type
  3. The oil viscosity
  4. The charge level
Answer: A — Whether moisture and heat have degraded the oil, signalling contamination or an impending or past burnout
Acid in the oil is the product of moisture reacting with refrigerant and oil under heat. A positive test means the system needs cleanup — filter-driers, possibly an oil change and a second drier — before it is put back into normal service.

74. After a compressor burnout, the recommended cleanup includes:

  1. Recharging immediately
  2. Installing suction-line and liquid-line filter-driers, and rechecking acid levels after a run period
  3. Adding extra oil
  4. Venting the acid
Answer: B — Installing suction-line and liquid-line filter-driers, and rechecking acid levels after a run period
A burnout leaves acid and carbon throughout the system. Suction-line and liquid-line driers capture it, and the acid test is repeated after a period of operation to confirm the cleanup worked — sometimes requiring a second set of driers.

75. Why does moisture in a system matter more than its quantity suggests?

  1. It adds weight
  2. It has no effect
  3. It changes the colour
  4. Small amounts form acids that attack windings and can freeze at the metering device
Answer: D — Small amounts form acids that attack windings and can freeze at the metering device
A few parts per million of water is enough to start acid formation that slowly destroys motor insulation, and free water can freeze at the expansion device and block flow entirely. Both failures are gradual, which is why they are designed out with evacuation rather than diagnosed later.

76. Mixing mineral oil into a POE system typically causes:

  1. Oil-return problems, because mineral oil is not miscible with HFC refrigerant and logs in the evaporator
  2. Improved lubrication
  3. Higher efficiency
  4. Nothing
Answer: A — Oil-return problems, because mineral oil is not miscible with HFC refrigerant and logs in the evaporator
Mineral oil will not mix with HFC refrigerant, so it separates and collects in the evaporator where refrigerant velocity cannot carry it back. The compressor is then starved of oil while the evaporator loses heat transfer surface.

77. Why is dry nitrogen, rather than shop air, used for pressure testing?

  1. Nitrogen is cheaper
  2. Shop air carries moisture and oil, which contaminate the system
  3. Nitrogen is heavier
  4. Air is illegal
Answer: B — Shop air carries moisture and oil, which contaminate the system
Compressed shop air brings water vapour and compressor oil into a system that is about to be evacuated and charged, undoing the point of the evacuation. Dry nitrogen is inert and moisture-free, and it may be released afterwards because it is not a regulated refrigerant.

78. A nitrogen cylinder must be used with a regulator because:

  1. It measures the flow
  2. It keeps the gas dry
  3. Nitrogen is corrosive
  4. Cylinder pressure of roughly 2,000 psi vastly exceeds system design pressure and would rupture components
Answer: D — Cylinder pressure of roughly 2,000 psi vastly exceeds system design pressure and would rupture components
Cracking a nitrogen valve straight into a system rated for a few hundred psi can burst a coil or a line instantly. The regulator brings it to a safe test pressure, and a relief valve downstream is a sensible second layer.

79. What must happen to the refrigerant before nitrogen pressure testing?

  1. It must be recovered, so the nitrogen released afterwards is not mixed with refrigerant
  2. Nothing
  3. It should be topped up
  4. It should be frozen
Answer: A — It must be recovered, so the nitrogen released afterwards is not mixed with refrigerant
Nitrogen may be released, but refrigerant may not. Pressurising on top of a remaining charge and then venting would release regulated refrigerant along with the nitrogen, which is a violation. Recovery comes first.

80. Adding a trace of refrigerant to nitrogen so an electronic detector can find the leak is:

  1. Always required
  2. Permitted in limited circumstances, but the mixture must not be vented and the practice is restricted
  3. Illegal in all cases
  4. Standard practice with no restrictions
Answer: B — Permitted in limited circumstances, but the mixture must not be vented and the practice is restricted
Trace-gas testing has historically been used, but the resulting mixture contains regulated refrigerant and therefore cannot be released to atmosphere, and the rule restricts the practice. Ultrasonic detection or a bubble solution on straight nitrogen avoids the problem.

81. During a standing pressure test, the pressure drops overnight. Before concluding there is a leak, check:

  1. The cylinder colour
  2. The compressor amps
  3. The oil level
  4. Whether ambient temperature fell, which lowers pressure independently of any leak
Answer: D — Whether ambient temperature fell, which lowers pressure independently of any leak
Gas pressure tracks absolute temperature, so a cold night drops the reading in a perfectly tight system. Recording temperature with pressure at both ends of the test and correcting for it is what makes the result meaningful.

82. Why should a technician never pressurise a system with oxygen?

  1. Oxygen reacts violently with refrigerant oil under pressure and can detonate
  2. It is expensive
  3. It causes rust
  4. It is too light
Answer: A — Oxygen reacts violently with refrigerant oil under pressure and can detonate
Compressed oxygen in contact with hydrocarbon oil ignites explosively — this has killed technicians. Dry nitrogen through a regulator is the only correct pressurising gas, and the two cylinders should never be confused.

83. What is the primary hazard of R-410A\u2019s higher operating pressure compared with R-22?

  1. It is more toxic
  2. Components and recovery equipment must be rated for the higher pressure, or they can rupture
  3. It is flammable
  4. It depletes ozone
Answer: B — Components and recovery equipment must be rated for the higher pressure, or they can rupture
R-410A runs at substantially higher pressures than R-22, so gauges, hoses, recovery machines, and cylinders all need appropriate ratings. Using R-22-rated equipment on R-410A risks a burst hose or gauge at working pressure.

84. Machinery rooms with large refrigerant charges require what safety provision?

  1. Carpeting
  2. Nothing special
  3. Extra lighting only
  4. Refrigerant vapour detection and mechanical ventilation
Answer: D — Refrigerant vapour detection and mechanical ventilation
A large release in an enclosed plant room displaces oxygen and can be fatal before anyone notices. Detection tied to mechanical ventilation and alarms is the standard requirement, and ASHRAE 15 is the reference standard behind it.

85. What personal protective equipment is appropriate when opening a high-pressure system?

  1. Eye protection and gloves resistant to liquid refrigerant
  2. Hearing protection only
  3. A hard hat only
  4. None
Answer: A — Eye protection and gloves resistant to liquid refrigerant
A high-pressure system holds liquid refrigerant that boils far below freezing, so any residual release is a frostbite and eye-injury risk. Splash-resistant eye protection and impermeable gloves are the minimum before breaking a connection.

86. A technician smells a sharp, acrid odour while brazing near a refrigeration system. This most likely indicates:

  1. Normal flux fumes only
  2. Refrigerant decomposing into acid gases, meaning refrigerant is still present
  3. Overheated copper
  4. A nitrogen leak
Answer: B — Refrigerant decomposing into acid gases, meaning refrigerant is still present
That smell is the signature of refrigerant breaking down into hydrofluoric and hydrochloric acids and, from chlorinated refrigerants, phosgene. The response is to stop, ventilate, leave the area, and determine why refrigerant is still in the system.

87. When a recovery cylinder has reached its fill limit mid-recovery, the technician should:

  1. Continue and overfill slightly
  2. Heat the cylinder to make room
  3. Vent the excess
  4. Close the cylinder, swap in an empty certified cylinder, and continue
Answer: D — Close the cylinder, swap in an empty certified cylinder, and continue
There is no acceptable margin past the 80% limit, and heating a nearly full cylinder makes the hazard worse rather than creating space. Swapping to a fresh, in-date cylinder is the only correct move.

88. Comparing measured condensing temperature against the saturation temperature for the observed head pressure helps detect:

  1. Non-condensable gases in the system
  2. Low charge
  3. A dirty evaporator
  4. A failed thermostat
Answer: A — Non-condensable gases in the system
If the head pressure corresponds to a saturation temperature meaningfully above the actual condensing temperature, the extra pressure is coming from something that will not condense — air. This comparison is the standard field test for non-condensables.

89. Automatic leak detection systems can substitute for what obligation?

  1. Recovery before service
  2. The periodic leak inspections required for appliances above the charge thresholds
  3. Technician certification
  4. Recordkeeping
Answer: B — The periodic leak inspections required for appliances above the charge thresholds
An owner who installs and maintains automatic leak detection on a covered appliance may use it in place of the scheduled inspections. It does not touch the repair deadlines, the verification tests, or any other part of the regime.

90. Records of leak repairs and verification tests must be retained for how long?

  1. 30 days
  2. 3 years
  3. 1 year
  4. Indefinitely
Answer: B — 3 years
Three years is the general Section 608 retention period and it covers leak-rate calculations, repair dates, and both verification tests. These are the records that demonstrate a chronic leaker was actually addressed rather than repeatedly topped up.

91. Before evacuating a system for service, the technician must first:

  1. Add nitrogen
  2. Run the compressor
  3. Open the system
  4. Recover the refrigerant to the required level using certified recovery equipment
Answer: D — Recover the refrigerant to the required level using certified recovery equipment
Evacuation follows recovery — a vacuum pump is not a recovery device, and running one on a charged system discharges refrigerant straight to atmosphere through the pump exhaust. Recovery first, then evacuation.

92. Why is a vacuum pump not a substitute for a recovery machine?

  1. A vacuum pump discharges to atmosphere, so using it on a charged system vents refrigerant
  2. It is slower
  3. It cannot reach a vacuum
  4. It has no oil
Answer: A — A vacuum pump discharges to atmosphere, so using it on a charged system vents refrigerant
A vacuum pump has no recovery cylinder — whatever it pulls out goes out the exhaust. Using one to empty a charged system is a textbook venting violation. Its role begins after the refrigerant is already in a cylinder.

93. Recovered refrigerant returned to the same owner\u2019s equipment after on-site recycling:

  1. Must be reclaimed first
  2. Does not require reclamation
  3. Must be destroyed
  4. Must be sold
Answer: B — Does not require reclamation
Refrigerant recovered and cleaned on site may go back into that same owner\u2019s equipment without reclamation. The AHRI 700 reclamation requirement attaches when the refrigerant changes ownership or is offered for sale.

94. Topping up a system known to be leaking above its threshold, without repair, is:

  1. Standard practice
  2. A violation of the leak repair requirements once the threshold and deadlines apply
  3. Permitted once a year
  4. Encouraged
Answer: B — A violation of the leak repair requirements once the threshold and deadlines apply
Once the appliance is over its threshold the clock starts: repair within 30 days, then two verification tests. Serial recharging in place of repair is precisely the behaviour the leak repair regime exists to stop.

95. A filter-drier should be replaced:

  1. Never
  2. Whenever the system is opened for major service or after contamination
  3. Only every ten years
  4. Only on new systems
Answer: B — Whenever the system is opened for major service or after contamination
A drier has finite capacity and a saturated one protects nothing. Replacing it whenever the system is opened, and always after a burnout or a moisture event, is standard practice — it is a cheap part guarding an expensive compressor.

96. Motor vehicle air conditioning is certified under which section of the Clean Air Act?

  1. Section 608
  2. Section 609
  3. Section 610
  4. Section 611
Answer: B — Section 609
Section 609 governs motor-vehicle air conditioning and has its own technician certification. A Section 608 Universal card does not by itself authorise MVAC service for consideration, which is a distinction that catches out technicians moving between shops.

97. Hoses used on R-410A systems must be:

  1. Any standard hose
  2. Rated for the higher working and burst pressures R-410A produces
  3. Made of copper
  4. Longer than 6 feet
Answer: B — Rated for the higher working and burst pressures R-410A produces
R-410A working pressures far exceed R-22\u2019s, so hoses, gauges, and fittings all need appropriate pressure ratings. A hose rated only for R-22 service can burst, and a burst hose under liquid pressure is a serious injury risk.

98. Low head pressure together with low suction pressure most often indicates:

  1. Overcharge
  2. An undercharge or a low ambient condition
  3. Non-condensables
  4. A dirty condenser
Answer: B — An undercharge or a low ambient condition
When both sides run low, the system usually does not have enough refrigerant to work with — or it is operating in cold ambient without head pressure control. Checking subcooling and ambient conditions separates the two before anyone adds refrigerant.

99. The correct way to release nitrogen after a successful pressure test is:

  1. Through the recovery machine
  2. To atmosphere, since nitrogen is not a regulated refrigerant and the system was recovered first
  3. Into a recovery cylinder
  4. It cannot be released
Answer: B — To atmosphere, since nitrogen is not a regulated refrigerant and the system was recovered first
Nitrogen is not regulated under Section 608 and may be released, provided the refrigerant was recovered before the test so that what you are releasing is nitrogen alone. Putting it through a recovery machine would only contaminate recovered refrigerant with non-condensables.

100. Why must a recovery machine be evacuated or purged before switching refrigerants?

  1. To save oil
  2. Residual refrigerant and oil cross-contaminate the next recovery and can render a cylinder unsaleable
  3. To reset the controls
  4. It is not necessary
Answer: B — Residual refrigerant and oil cross-contaminate the next recovery and can render a cylinder unsaleable
Whatever remains inside the machine joins the next charge you pull. A mixed cylinder cannot be reclaimed normally and must go for destruction, so a few minutes of changeover procedure protects both the refrigerant\u2019s value and the next system you charge.
Other Sections
Keep Practicing
Practice Test

EPA 608 Core

Refrigerant fundamentals, regulations, safety, and recovery practice.

100 questions
Practice Test

EPA 608 Type I

Small appliances — factory-sealed systems holding 5 pounds of refrigerant or less.

100 questions
Practice Test

EPA 608 Type III

Low-pressure appliances — centrifugal chillers operating below atmospheric pressure.

100 questions
Full Exam

EPA 608 Universal

All four sections in one 100-question attempt, scored section by section.

100 questions

Read the full EPA 608 certification guide for exam costs, testing organizations, and how to choose between Type I, II, III, and Universal.

FAQ
EPA 608 Type II Questions
How many questions are on the EPA 608 Type II exam?
The Type II section is 25 multiple-choice questions. 25 multiple-choice questions taken with Core, proctored and open-book, 70% to pass. Passing Core plus Type II is the practical minimum most HVAC employers expect.
What score do I need to pass EPA 608 Type II?
You need 70% — 18 of 25 questions — to pass. Each section is scored independently, so passing Core does not offset a failing Type II score, and you must pass both to be certified for type ii work.
Who needs EPA 608 Type II certification?
Most working HVAC technicians. Type II covers residential split systems, rooftop units, heat pumps, and commercial refrigeration. High-pressure and very high-pressure appliances — residential and commercial AC, heat pumps, and refrigeration.
Is this practice test the real EPA 608 exam?
No. This is free study material written from the published rule in 40 CFR Part 82, Subpart F — it does not reproduce exam content. The real exam is proctored and administered by an EPA-approved certifying organization, and it is open-book, so bring your study guide.
Does EPA 608 Type II certification expire?
No. Section 608 certification is issued for life under the current rule. There is no renewal requirement and no continuing education, though you must keep proof of certification at your place of business.
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