EPA Section 608 Certification — Questions and Answers

Question 1: Which of the following refrigerant groups does R-22 belong to?

HFC
CFC
All of the above
HCFC (Correct answer)

Correct answer: HCFC

R-22, chemically known as chlorodifluoromethane, belongs to the Hydrochlorofluorocarbon (HCFC) group of refrigerants. HCFCs contain hydrogen, chlorine, fluorine, and carbon, and while they have a lower ozone depletion potential than CFCs, they are still regulated and are being phased out due to their impact on the ozone layer.

Question 2: Which component is present in all four types of vapor-compression refrigeration cycles (small appliances, high-pressure, low-pressure, and automotive)?

Receiver-drier
Accumulator
Purge unit
Compressor (Correct answer)

Correct answer: Compressor

All vapor-compression refrigeration systems — regardless of size, pressure, or application — require a compressor to circulate refrigerant through the cycle by compressing low-pressure vapor into high-pressure vapor. Receiver-driers are found in most but not all systems; accumulators are specific to certain configurations; purge units are unique to low-pressure centrifugal chillers.

Question 3: Refrigerant recovered from a small appliance and sent off-site to be returned to manufacturer specs must be processed by which entity?

A certified reclaimer (Correct answer)
Any HVAC shop
The refrigerant wholesaler
The local landfill

Correct answer: A certified reclaimer

Refrigerant returned to new-product purity (ARI 700) for sale to another owner must be processed by an EPA-certified reclaimer.

Question 4: Records of refrigerant recovered from appliances being disposed of should be kept to demonstrate what?

Energy savings
Customer satisfaction
Sales totals
Regulatory compliance (Correct answer)

Correct answer: Regulatory compliance

Documentation demonstrates compliance with EPA refrigerant handling regulations.

Question 5: Which type of leak detector is considered the most sensitive and can detect refrigerant concentrations in the parts-per-billion range?

Halide torch
Heated diode detector
Infrared (IR) sensor detector (Correct answer)
Ultrasonic acoustic detector

Correct answer: Infrared (IR) sensor detector

Infrared (IR) sensor detectors are among the most sensitive refrigerant detection instruments, capable of detecting concentrations in the parts-per-billion range. They work by measuring the absorption of infrared light by refrigerant molecules, providing precise and reliable detection across multiple refrigerant types.

Question 6: When recovering refrigerant into a cylinder, the cylinder should never be filled beyond what percentage of its capacity by weight?

50%
95%
80% (Correct answer)
60%

Correct answer: 80%

Recovery cylinders must not be filled beyond 80% to allow for liquid expansion.

Question 7: Under the EPA's venting prohibition under Section 608, which of the following refrigerants is NOT subject to the prohibition?

R-134a (HFC)
R-410A (HFC)
R-22 (HCFC)
CO2 (R-744) used as a refrigerant substitute (Correct answer)

Correct answer: CO2 (R-744) used as a refrigerant substitute

The EPA's venting prohibition under Section 608 applies to CFCs, HCFCs, and HFCs used as refrigerants. The EPA has not extended the venting prohibition to substitute refrigerants like CO2 (R-744) in the same regulatory framework, though responsible handling is always expected. CFCs, HCFCs, and HFCs are all subject to the ban.

Question 8: Technicians who work on small appliances with sealed systems must have:

Type I, II, or III certification
Type II certification
Type I or Universal certification (Correct answer)
Universal 609 certification

Correct answer: Type I or Universal certification

Under EPA Section 608 regulations, technicians who work on small appliances (defined as factory-sealed units containing 5 pounds or less of refrigerant) must hold either a Type I certification or a Universal certification. These certifications demonstrate the technician's knowledge and ability to safely handle refrigerants in these specific types of equipment.

Question 9: What does MVAC stand for in the context of EPA Section 609?

Mobile Ventilation and Cooling
Manifold Valve Assembly Circuit
Multi-Vehicle Automotive Coolant
Motor Vehicle Air Conditioning (Correct answer)

Correct answer: Motor Vehicle Air Conditioning

MVAC stands for Motor Vehicle Air Conditioning. EPA Section 609 specifically regulates the servicing of MVAC systems in motor vehicles, requiring that technicians use approved refrigerant recovery/recycling equipment and be certified to handle refrigerants used in these systems.

Question 10: Never pressurize a system with compressed air or oxygen because

the pressure produced by either oxygen or compressed air are not as good as nitrogen pressures.
leaking oxygen or compressed air is more difficult to detect than nitrogen.
when mixed with compressor oil or some refrigerants, it could explode. (Correct answer)
oxygen and compressed air do not mix with refrigerants.

Correct answer: when mixed with compressor oil or some refrigerants, it could explode.

Pressurizing a refrigeration system with compressed air or oxygen is extremely dangerous and strictly prohibited. When mixed with compressor oil or certain refrigerants, oxygen can create a highly combustible mixture, leading to a severe explosion. Nitrogen, an inert gas, is the safe and recommended choice for leak testing and purging.

Question 11: A Type II system has an evaporator saturation temperature of 20°F and a suction line temperature of 45°F. What is the suction line superheat?

65°F
25°F (Correct answer)
20°F
45°F

Correct answer: 25°F

Superheat equals the actual suction line temperature minus the saturation temperature at the suction pressure. 45°F (actual) − 20°F (saturation) = 25°F superheat. This value falls within a typical acceptable range for many commercial refrigeration systems. Technicians use this calculation to evaluate whether the expansion device is feeding the evaporator correctly.

Question 12: When servicing an MVAC system, refrigerant must be:

Vented to the atmosphere
Poured into a drain
Burned off
Recovered using approved equipment (Correct answer)

Correct answer: Recovered using approved equipment

Refrigerant must be recovered with approved equipment, not vented.

Question 13: What characterizes a low-pressure refrigerant serviced under Type III certification?

It contains no chlorine
It boils below atmospheric pressure at room temperature (Correct answer)
It operates above 50 psig
It is always flammable

Correct answer: It boils below atmospheric pressure at room temperature

Low-pressure refrigerants such as R-123 boil at or below atmospheric pressure at normal temperatures.

Question 14: The sale of CFC-12 (R-12) in containers smaller than 20 pounds is restricted to whom?

Technicians who are certified under Section 609. (Correct answer)
Only licensed automotive repair shops.
Anyone, as long as it is for personal use.
Only technicians who are certified under Section 608.

Correct answer: Technicians who are certified under Section 609.

EPA regulations specifically state that the sale of ozone-depleting substances like CFC-12 in containers of less than 20 pounds is restricted to technicians who have been certified under an EPA-approved Section 609 program. Sellers are required to verify the purchaser's certification.

Question 15: The state of a refrigerant leaving a refrigeration system's liquid receiver is:

Low-Pressure Gas
High-Pressure Liquid (Correct answer)
High-Pressure Gas
Low-Pressure Liquid

Correct answer: High-Pressure Liquid

The liquid receiver in a refrigeration system stores excess liquid refrigerant after it has condensed in the condenser. Therefore, the refrigerant leaving the receiver is in a high-pressure liquid state. This ensures a constant supply of liquid refrigerant to the expansion device, maintaining proper system operation.

Question 16: What percentage of refrigerant must remain in a system operating above atmospheric pressure for a passive recovery process to stop, according to EPA efficiency standards?

The system must reach 0 psig or lower
Recovery must reduce system pressure to 4 inches of mercury vacuum (Correct answer)
90%
80%

Correct answer: Recovery must reduce system pressure to 4 inches of mercury vacuum

For systems with a full charge of less than 200 pounds operating above atmospheric pressure, the EPA requires passive recovery to continue until the system pressure reaches 4 inches of mercury vacuum (approximately -13.5 psi). This ensures that the maximum practical amount of refrigerant is captured and not vented to the atmosphere.

Question 17: Which type of recovery device must be used when recovering refrigerant from a system that contains a near-azeotropic blend like R-410A?

No recovery is needed
Passive recovery only
Vapor recovery only
Liquid recovery to avoid fractionation (Correct answer)

Correct answer: Liquid recovery to avoid fractionation

Blends should be recovered in the liquid phase to prevent fractionation that changes their composition.

Question 18: Which of these is a primary health hazard of breathing high concentrations of refrigerant vapor?

Hyperthermia
Increased blood pressure
Cardiac sensitization and asphyxiation (Correct answer)
Improved oxygen uptake

Correct answer: Cardiac sensitization and asphyxiation

High refrigerant concentrations displace oxygen and can sensitize the heart, risking asphyxiation and cardiac arrhythmia.

Question 19: How does a refrigerant's "vapor pressure" affect the type of recovery equipment needed?

Higher vapor pressure refrigerants require vacuum pumps; lower vapor pressure refrigerants only need gravity recovery
Vapor pressure has no effect on recovery equipment selection
All refrigerants use identical recovery equipment regardless of vapor pressure
High vapor pressure (high-pressure) refrigerants require compressor-based recovery; very low-pressure refrigerants may use heat and temperature differential methods (Correct answer)

Correct answer: High vapor pressure (high-pressure) refrigerants require compressor-based recovery; very low-pressure refrigerants may use heat and temperature differential methods

Refrigerant vapor pressure at operating temperatures determines the recovery approach. High-pressure refrigerants (R-22, R-410A) have significant vapor pressure at room temperature, requiring compressor-based recovery machines to capture them efficiently. Low-pressure refrigerants (R-11, R-123) have very low vapor pressures and can sometimes be recovered using heat applied to the evaporator to drive refrigerant toward the recovery cylinder. Equipment selection must match refrigerant characteristics.

Question 20: The EPA would approve the CO2 system if the MVAC system was designed to avoid concentrations in the passenger cabin that are _____ above for more than 15 minutes.

2.50%
1.50%
4.50%
3% (Correct answer)

Correct answer: 3%

The EPA would approve a CO2 MVAC system if it is designed to prevent CO2 concentrations in the passenger cabin from exceeding 3% above ambient for more than 15 minutes. This regulation is in place to ensure passenger safety, as high concentrations of CO2 can pose health risks. Proper system design and ventilation are critical for CO2-based MVAC systems.

Question 21: How long are owners of refrigerant recovery and recycling equipment required to retain service records under EPA Section 608?

5 years
1 year
3 years (Correct answer)
2 years

Correct answer: 3 years

EPA Section 608 requires that records related to refrigerant recovery, recycling, and reclamation activities be retained for a minimum of 3 years and be made available to EPA inspectors upon request.

Question 22: A halide torch leak detector indicates a refrigerant leak by changing what?

Pitch of a sound
Dye fluorescence
Pressure reading
Flame color to green (Correct answer)

Correct answer: Flame color to green

A halide torch flame turns green when it contacts chlorinated refrigerant.

Question 23: Which piece of equipment is designed to clean refrigerant on-site by removing oil, moisture, and other contaminants so it can be reused in a system owned by the same person?

A recycling unit (Correct answer)
A vacuum pump
A recovery cylinder
A reclamation unit

Correct answer: A recycling unit

Recycling equipment is used to clean refrigerant by extracting it and passing it through devices like filter-driers to reduce contaminants. This allows the refrigerant to be reused in equipment belonging to the same owner.

Question 24: Mixing two different refrigerants in one recovery cylinder is:

Recommended to save space
Required by EPA
Prohibited because the mix cannot be reclaimed (Correct answer)
Acceptable if both are HCFCs

Correct answer: Prohibited because the mix cannot be reclaimed

Mixed refrigerants cannot be reclaimed and must be costly destroyed, so mixing is prohibited.

Question 25: Type II certification is required to service which of the following?

High-pressure and very high-pressure appliances (Correct answer)
Small appliances
Low-pressure appliances
Automobile A/C

Correct answer: High-pressure and very high-pressure appliances

Type II certification covers high-pressure and very high-pressure equipment such as residential A/C and supermarket racks.

Question 26: As of 2020, the production and import of new HCFC-22 in the United States have been phased out. How can a technician legally obtain R-22 to service existing equipment?

By importing small quantities for personal use.
By purchasing it from an uncertified online reseller.
By using newly manufactured R-22 produced after the ban.
By using refrigerant that has been recovered, recycled, or reclaimed. (Correct answer)

Correct answer: By using refrigerant that has been recovered, recycled, or reclaimed.

While new production and import of R-22 were banned starting January 1, 2020, its use is still permitted for servicing existing systems. The only legal sources for R-22 are stockpiles produced before the ban or refrigerant that has been properly recovered and then recycled or reclaimed to meet AHRI-700 purity standards.

Question 27: What does it mean when a refrigerant cylinder feels unusually light but pressure gauge shows normal pressure for that refrigerant?

The cylinder is full — pressure indicates fullness, not weight
The cylinder may be nearly empty — pressure remains constant until all liquid is gone, then drops (Correct answer)
High ambient temperature is compressing the gas to show false full pressure
The refrigerant has separated into its blend components, showing false pressure

Correct answer: The cylinder may be nearly empty — pressure remains constant until all liquid is gone, then drops

A refrigerant cylinder contains both liquid and vapor phases as long as any liquid remains. The pressure stays constant at the saturation pressure for that temperature regardless of how much liquid is left — only when all liquid evaporates does pressure begin to drop. Therefore, cylinder weight (tare + net refrigerant) is the only accurate way to determine remaining charge. A light cylinder may be nearly empty even at full saturation pressure.

Question 28: The ozone layer absorbs and scatters ________ from the sun.

infrared light
ultraviolet light (Correct answer)
x-radiation
gamma radiation

Correct answer: ultraviolet light

The ozone layer, located in the stratosphere, plays a vital role in protecting life on Earth by absorbing and scattering harmful ultraviolet (UV) light from the sun. Specifically, it blocks most of the sun's UVB radiation, which can cause skin cancer, cataracts, and harm to ecosystems. Without the ozone layer, life on Earth would be severely impacted by this intense radiation.

Question 29: How do technicians most reliably detect leaks in a Type III low-pressure chiller system during operation?

Pressurizing the system with nitrogen and checking for bubbles
Using an ultrasonic detector tuned for high-pressure refrigerant escape
Monitoring for a rise in system pressure caused by air infiltration (Correct answer)
Looking for ice or frost formation on refrigerant fittings

Correct answer: Monitoring for a rise in system pressure caused by air infiltration

Because Type III systems operate under vacuum, any leak allows atmospheric air to enter rather than refrigerant to escape. This air infiltration raises the internal pressure above the normal operating vacuum. Technicians watch for unexpected pressure rise as a primary leak indicator. Nitrogen pressurization is used for some leak checks but is not the primary operational detection method.

Question 30: Which refrigerant type has zero ozone depletion potential but can still have a high global warming potential?

Halons
HFCs (Correct answer)
CFCs
HCFCs

Correct answer: HFCs

HFCs contain no chlorine so have zero ODP, but many have high GWP.

Question 31: Before switching to liquid charging on an R-410a system with a water-cooled condenser, you must first charge with vapor to a pressure of at least ________.

320 psig
120 psig (Correct answer)
20 psig
220 psig

Correct answer: 120 psig

When charging an R-410a system, it's essential to initially charge with vapor until the system pressure reaches at least 120 psig. This prevents the liquid refrigerant from slugging the compressor, which can cause severe damage. Once this pressure is achieved, liquid charging can safely commence, as the compressor is less likely to be damaged by liquid refrigerant at higher system pressures.

Question 32: Why should a technician evacuate from both the high and low sides of a refrigeration system?

Because DOT requires dual-port evacuation
To measure superheat from both sides simultaneously
To increase system operating pressure
To achieve faster and more thorough evacuation past any closed internal valves (Correct answer)

Correct answer: To achieve faster and more thorough evacuation past any closed internal valves

Evacuating from both service ports removes non-condensables and moisture more quickly and ensures no section of the system is isolated from the vacuum.

Question 33: PAG oil used in R-134a MVAC systems must be stored and handled carefully for which reason?

PAG oil reacts explosively with water at room temperature
PAG oil must be kept below 40°F or it permanently loses its viscosity properties
PAG oil is incompatible with rubber hoses and must only contact metal fittings
PAG oil is highly hygroscopic and absorbs moisture rapidly from the atmosphere (Correct answer)

Correct answer: PAG oil is highly hygroscopic and absorbs moisture rapidly from the atmosphere

PAG (polyalkylene glycol) oil is highly hygroscopic — it absorbs moisture from the air very rapidly when exposed. Moisture in refrigerant oil creates acid that damages compressor bearings, valves, and motor windings. Always keep PAG oil containers sealed when not in use, use clean dedicated equipment for oil handling, and minimize air exposure time during oil addition procedures.

Question 34: Under Section 609, small cans of refrigerant (2 pounds or less) for MVAC top-off use sold at retail stores may be purchased by:

Only EPA Section 609 certified technicians
The general public without certification requirements (Correct answer)
Any person over age 18 with a state ID
Only licensed automotive repair shops

Correct answer: The general public without certification requirements

EPA Section 609 regulations allow small containers of 2 pounds or less of MVAC refrigerant to be sold to the general public without requiring certification. These small "top-off" cans are available at auto parts stores for consumer use. The certification requirement applies to technicians purchasing refrigerant in larger quantities for professional service work.

Question 35: When recovering refrigerant from a low-pressure appliance for major repair, the required recovery level depends on:

The size of the building
The ambient humidity
The technician's experience level
Whether recovery/recycling equipment was made before or after Nov 15, 1993 (Correct answer)

Correct answer: Whether recovery/recycling equipment was made before or after Nov 15, 1993

Required recovery vacuum levels differ for equipment manufactured before versus after November 15, 1993.

Question 36: What minimum pressure rating must recovery cylinders meet for use with R-410A refrigerant?

400 psig (Correct answer)
500 psig
250 psig
350 psig

Correct answer: 400 psig

R-410A operates at much higher pressures than older refrigerants, requiring recovery cylinders rated at a minimum of 400 psig (DOT-4BA400 or equivalent).

Question 37: During the recovery process, there is a strong odor. Which of the following is most likely to be the source of the problem?

All of the Above
Condenser Burnout
Compressor Burnout (Correct answer)
Accumulator Burnout

Correct answer: Compressor Burnout

A strong, acrid odor during the recovery process is a telltale sign of a compressor burnout. When a compressor motor burns out, the high temperatures cause the refrigerant and oil to decompose, forming acids and other foul-smelling byproducts. This contamination can severely damage other components of the refrigeration system if not properly addressed.

Question 38: Which refrigerant is classified as a high-pressure refrigerant and commonly used in commercial refrigeration Type II systems?

R-113 (low-pressure)
R-123 (low-pressure)
R-11 (low-pressure)
R-404A (high-pressure) (Correct answer)

Correct answer: R-404A (high-pressure)

R-404A is a high-pressure HFC refrigerant blend commonly used in commercial refrigeration, supermarket display cases, and transport refrigeration (Type II systems). R-11, R-113, and R-123 are low-pressure refrigerants that operate below atmospheric pressure at room temperature, requiring Type III certification to service.

Question 39: A rupture disk in a low-pressure system will open at which of the following psig?

15 psig (Correct answer)
20 psig
25 psig
10 psig

Correct answer: 15 psig

Rupture disks are critical safety devices in low-pressure refrigeration systems, designed to prevent over-pressurization. EPA regulations mandate that these disks must open at 15 psig to safely release refrigerant. This specific pressure setting protects the system's components from damage and ensures the safety of personnel by preventing catastrophic failure.

Question 40: Which refrigerant blend is classified as zeotropic (near-azeotropic)?

R-502
R-507A
R-407C (Correct answer)
R-500

Correct answer: R-407C

R-407C is a zeotropic HFC blend of R-32, R-125, and R-134a that exhibits temperature glide because its components have different boiling points.

Question 41: What is the ASHRAE/ARI standard cylinder color for R-22 refrigerant?

Green (Correct answer)
Yellow
Light blue
Rose (pink)

Correct answer: Green

ASHRAE/ARI assigns green as the standard cylinder color for R-22 to prevent misidentification during service.

Question 42: A high-pressure appliance with a capacity of less than 200 pounds. The level of an HCFC or HFC refrigerant must be evacuated (recovered) to:

10 inches of vacuum
4 inches of vacuum
15 inches of vacuum
0 inches of vacuum (Correct answer)

Correct answer: 0 inches of vacuum

For high-pressure appliances with a capacity of less than 200 pounds of HCFC or HFC refrigerant, the EPA requires evacuation to 0 inches of vacuum (0 psig). This means the system must be pulled down to atmospheric pressure. This standard ensures that a significant amount of refrigerant is recovered, minimizing environmental release.

Question 43: Which of the following best describes 'recycling' refrigerant in the MVAC context?

Diluting it with nitrogen
Burning it for disposal
Cleaning refrigerant on-site to SAE standards for reuse in vehicles (Correct answer)
Sending it to a federal lab

Correct answer: Cleaning refrigerant on-site to SAE standards for reuse in vehicles

Recycling means cleaning refrigerant on-site to SAE purity standards so it can be reused.

Question 44: A technician recovers refrigerant from a Type I small appliance and wants to reuse it in another similar system. What must be done with the recovered refrigerant before it can be legally recharged into a different owner's equipment?

It must be tested for moisture content only
It must be recycled or reclaimed to ARI 700 purity standards (Correct answer)
It can be recharged directly without any processing
It must be destroyed by an EPA-approved facility

Correct answer: It must be recycled or reclaimed to ARI 700 purity standards

Recovered refrigerant that will be used in a different owner's equipment must be reclaimed to ARI 700 standards by a certified reclaimer. Simply recycling on-site is only acceptable when recharging the same system or a system owned by the same owner.

Question 45: Which of the following is a key requirement under the EPA Section 608 regulations for technicians handling refrigerants?

They must have a degree in mechanical engineering.
They must renew their certification every two years.
They must pass an EPA-approved certification exam. (Correct answer)
They must be a member of an HVAC trade organization.

Correct answer: They must pass an EPA-approved certification exam.

Section 608 of the Clean Air Act mandates that any person who maintains, services, repairs, or disposes of equipment that could release regulated refrigerants into the atmosphere must be certified by passing an EPA-approved examination.

Question 46: Equipment for recovery must be:

CSA approved.
Certified by an EPA-approved testing laboratory. (Correct answer)
Used on all equipment manufactured after November 15, 1995.
Used on all equipment manufactured after July 1, 1995.

Correct answer: Certified by an EPA-approved testing laboratory.

EPA regulations under Section 608 mandate that all refrigerant recovery and recycling equipment must be certified by an EPA-approved testing laboratory. This certification ensures that the equipment meets specific performance standards for efficiency and effectiveness in recovering refrigerants, thereby minimizing their release into the atmosphere during servicing.

Question 47: A potentially dangerous condition when adding nitrogen to pressurize a low-pressure system for leak testing is exceeding:

150 psig
500 psig
50 psig
10 psig (Correct answer)

Correct answer: 10 psig

Low-pressure appliances should not be pressurized above 10 psig, as higher pressures can cause a violent rupture.

Question 48: Why should refrigerant cylinders never be overfilled?

Risk of rupture from thermal expansion (Correct answer)
It is required by SAE
It saves money
They cool better when full

Correct answer: Risk of rupture from thermal expansion

Overfilled cylinders can rupture when liquid expands with temperature increases.

Question 49: Ultrasonic leak detectors work by sensing what?

Flame color
High-frequency sound made by gas escaping a leak (Correct answer)
Magnetic field changes
Refrigerant odor

Correct answer: High-frequency sound made by gas escaping a leak

Escaping gas produces high-frequency sound that ultrasonic detectors pick up.

Question 50: What is the primary environmental consequence of refrigerant CFCs and HCFCs reaching the stratosphere?

They create smog by reacting with ground-level ozone
They absorb solar radiation, directly increasing surface temperatures
They catalytically destroy ozone molecules, thinning the protective ozone layer (Correct answer)
They increase acid rain by reacting with nitrogen oxides

Correct answer: They catalytically destroy ozone molecules, thinning the protective ozone layer

CFCs and HCFCs release chlorine atoms when exposed to UV radiation in the stratosphere. Each chlorine atom catalytically destroys thousands of ozone molecules (O3 → O2 + O) through a chain reaction. Thinning of the ozone layer allows more UV-B radiation to reach Earth's surface, increasing skin cancer rates, cataracts, and damage to ecosystems and marine phytoplankton.

Question 51: What is the main purpose of EPA refrigerant certification programs?

Protect the ozone layer and reduce emissions (Correct answer)
Raise prices
License auto repair
Track sales tax

Correct answer: Protect the ozone layer and reduce emissions

The programs aim to protect stratospheric ozone and minimize refrigerant emissions.

Question 52: R-134a MVAC systems typically operate with what high-side pressure range at normal ambient temperatures (approximately 90°F)?

50-80 psig
300-400 psig
180-250 psig (Correct answer)
100-150 psig

Correct answer: 180-250 psig

R-134a automotive A/C systems typically operate with high-side pressures of approximately 180-250 psig at 90°F ambient temperature with the engine running and A/C at full cooling. Pressures vary with ambient temperature, compressor speed, and load. High-side pressures significantly outside this range indicate system problems such as overcharge, condenser airflow obstruction, or refrigerant contamination.

Question 53: Excessive subcooling at the condenser outlet of an R-22 system often indicates:

Overcharge or restricted liquid line (Correct answer)
Low head pressure
High superheat
Undercharge

Correct answer: Overcharge or restricted liquid line

High subcooling commonly results from overcharge or a liquid-line restriction.

Question 54: The EPA Section 609 certification specifically applies to technicians servicing which type of equipment?

Industrial chillers
Residential central air conditioners
Motor vehicle air conditioning (MVAC) systems (Correct answer)
Commercial walk-in freezers

Correct answer: Motor vehicle air conditioning (MVAC) systems

Section 609 certification covers technicians who repair or service motor vehicle air conditioning systems.

Question 55: To speed up the recovery process from a system, a technician may do all of the following EXCEPT:

Heat the recovery cylinder to raise its pressure above the system (Correct answer)
Pack the recovery cylinder in ice to lower its pressure
Recover liquid first when possible
Use large-diameter, short hoses

Correct answer: Heat the recovery cylinder to raise its pressure above the system

The recovery cylinder should be cooled, not heated, to maintain a pressure difference that draws refrigerant in.

Question 56: Which certification would a technician need to work on a large supermarket rack system?

Section 609
Type II (Correct answer)
Type III
Type I

Correct answer: Type II

Large high-pressure commercial refrigeration falls under Type II.

Question 57: What must be done to a refrigerant cylinder before returning it to a supplier?

Close the valve and install the protective cap (Correct answer)
Hydrostatically test it
Empty it completely to 0 psig
Repaint it the correct color

Correct answer: Close the valve and install the protective cap

Before returning cylinders, technicians must close the valve and install the valve protection cap to prevent damage during handling and transport.

Question 58: A Type I certified technician services which of the following?

A 50-ton rooftop unit
A car AC system
A household refrigerator (Correct answer)
A centrifugal chiller

Correct answer: A household refrigerator

Household refrigerators are small appliances covered by Type I.

Question 59: A high-pressure appliance must be evacuated before disposal to ensure:

No refrigerant is vented during scrapping (Correct answer)
Faster shredding
Higher head pressure
Better resale value

Correct answer: No refrigerant is vented during scrapping

Evacuating before disposal prevents illegal venting when the unit is scrapped.

Question 60: Heating the refrigerant in a low-pressure appliance during recovery is used to:

Convert it to a high-pressure refrigerant
Damage the compressor
Speed up recovery by raising vapor pressure (Correct answer)
Reduce the charge weight

Correct answer: Speed up recovery by raising vapor pressure

Gently warming the refrigerant raises its pressure, allowing faster and more complete recovery.

Question 61: Using a recovery cylinder that already contains refrigerant from a different system is acceptable only if:

Never under any circumstances
It has been more than 5 years
It is the same refrigerant type and the 80% fill limit is observed (Correct answer)
The pressures are equal regardless of type

Correct answer: It is the same refrigerant type and the 80% fill limit is observed

You may add to a cylinder only when it holds the same refrigerant type and the combined charge stays under the 80% fill limit.

Question 62: What is the maximum civil penalty the EPA can assess per day per violation of refrigerant regulations?

Up to $10,000
Over $40,000 (Correct answer)
There is no penalty
Up to $1,000

Correct answer: Over $40,000

Violations can carry civil penalties exceeding $40,000 per day per violation.

Question 63: Type I certification covers servicing which kind of appliance?

Small appliances with 5 lbs or less of refrigerant (Correct answer)
Low-pressure chillers
High-pressure systems over 50 lbs
Motor vehicle air conditioners

Correct answer: Small appliances with 5 lbs or less of refrigerant

Type I certification is for small appliances manufactured, charged, and hermetically sealed with 5 pounds or less of refrigerant.

Question 64: What type of oil must be used with R-410A systems in Type II high-pressure applications?

Mineral oil
Polyol ester (POE) oil (Correct answer)
Alkylbenzene (AB) oil
Polyvinyl ether (PVE) oil

Correct answer: Polyol ester (POE) oil

R-410A and other HFC refrigerants require polyol ester (POE) oil because mineral oil and alkylbenzene oil are not miscible with HFCs. Miscibility (the ability to mix with refrigerant) is essential for proper oil return through the system. POE oil absorbs moisture readily, so systems using POE must be protected from atmospheric exposure during service.

Question 65: Recovery equipment manufactured after November 15, 1993, must evacuate a low-pressure appliance to:

25 mm Hg absolute (Correct answer)
0 psig
29 inches of vacuum
15 inches of vacuum

Correct answer: 25 mm Hg absolute

Post-1993 recovery equipment must achieve 25 mm Hg absolute on low-pressure appliances.

Question 66: Refrigerant that has been processed to meet AHRI Standard 700 purity is considered what?

Recycled
Reclaimed (Correct answer)
Disposed
Recovered

Correct answer: Reclaimed

Reclaimed refrigerant has been reprocessed to meet AHRI 700 new-product purity specifications.

Question 67: Which of the following refrigerants has the least or no potential for ozone depletion:

CFCs
FCs
HFCs (Correct answer)
HCFCs

Correct answer: HFCs

Hydrofluorocarbons (HFCs) have the least or no potential for ozone depletion because they do not contain chlorine atoms. Unlike CFCs and HCFCs, which release ozone-destroying chlorine in the stratosphere, HFCs are composed only of hydrogen, fluorine, and carbon. While HFCs are potent greenhouse gases, they are considered ozone-friendly alternatives.

Question 68: On-site recycling of recovered refrigerant means the refrigerant has been:

Processed to AHRI 700 virgin purity standards
Cleaned using oil separation and single-pass filtering at the job site (Correct answer)
Sent to a certified reclaimer and returned to the original owner
Distilled and separated from all contaminants by a licensed laboratory

Correct answer: Cleaned using oil separation and single-pass filtering at the job site

On-site recycling involves cleaning recovered refrigerant using oil separation and single-pass (or multiple-pass) filtering at the service location using portable recycling equipment. Recycled refrigerant may only be returned to the same system or other systems owned by the same person — it cannot be sold to a new owner, which requires full reclamation to AHRI 700 standards.

Question 69: A high-pressure appliance with 50 lbs of charge that is not being disposed of must be repaired within how many days of a leak being detected?

10 days
90 days
60 days
30 days (Correct answer)

Correct answer: 30 days

Leaks on appliances with 50+ lbs of charge generally must be repaired within 30 days.

Question 70: What is the purpose of a "pump-down" cycle in a Type II split system?

To evacuate the entire refrigerant charge into a recovery cylinder
To move the refrigerant charge into the outdoor condenser/receiver before service or shutdown (Correct answer)
To lower system pressure to atmospheric before changing filters
To remove air from the suction line before startup

Correct answer: To move the refrigerant charge into the outdoor condenser/receiver before service or shutdown

A pump-down cycle uses the compressor to transfer refrigerant from the low side into the condenser and receiver (liquid storage area) on the high side before service or extended shutdown. By isolating the refrigerant in the outdoor unit, the technician can work on indoor components (evaporator, TXV, etc.) with minimal refrigerant exposure. It is not a substitute for full recovery when opening the system.

Question 71: Which EPA 608 certification type covers hermetically sealed systems containing 5 pounds or less of CFC or HCFC refrigerant?

Type III
Universal
Type I (Correct answer)
Type II

Correct answer: Type I

Type I certification under EPA Section 608 covers small appliances — hermetically sealed systems manufactured, charged, and tested at the factory, containing 5 pounds or less of CFC or HCFC refrigerant. Examples include household refrigerators, window air conditioners, and dehumidifiers. Type I technicians use different recovery techniques appropriate for these sealed systems.

Question 72: When recovering refrigerant from a Type I small appliance using a system-dependent (passive) recovery method, the technician must recover refrigerant to what level before opening the system?

10 inches of mercury vacuum
4 inches of mercury vacuum (Correct answer)
15 inches of mercury vacuum
0 psig

Correct answer: 4 inches of mercury vacuum

For system-dependent recovery on small appliances where the compressor is operational, the EPA requires the technician to recover refrigerant to 4 inches of mercury vacuum before opening the system for repairs or disposal.

Question 73: Under what authority is the technician certification program established?

The Clean Water Act
OSHA standards
The Clean Air Act (Correct answer)
DOT regulations

Correct answer: The Clean Air Act

Section 608 of the Clean Air Act establishes the technician certification program.

Question 74: What proof must a certified technician be able to provide on request?

A refrigerant invoice
A college degree
Their certification card or proof of certification (Correct answer)
A business license

Correct answer: Their certification card or proof of certification

Technicians must present proof of certification when requested.

Question 75: Which of the following best describes the Global Warming Potential (GWP) comparison between R-134a and R-1234yf?

R-134a has a GWP of about 4, while R-1234yf has a GWP of about 1,430
R-134a has a GWP of about 1,430, while R-1234yf has a GWP of about 4 (Correct answer)
R-1234yf has a higher GWP than R-134a, which is why it is being phased out
Both refrigerants have an identical GWP of approximately 150

Correct answer: R-134a has a GWP of about 1,430, while R-1234yf has a GWP of about 4

R-134a has a Global Warming Potential (GWP) of approximately 1,430, meaning it is 1,430 times more potent than CO2 as a greenhouse gas over 100 years. R-1234yf has a GWP of only about 4, making it far more climate-friendly and driving its adoption in new vehicles under EPA regulations.

Question 76: If a technician fails one type but passes Core, what happens?

They get Type I automatically
They must retake Core
They keep credit for Core and retake only the failed type (Correct answer)
They lose all credit

Correct answer: They keep credit for Core and retake only the failed type

Core credit is retained, so only the failed type section must be retaken.

Question 77: You should never do this when a system is in a deep vacuum:

energize system fans and blowers.
use a micron gauge.
energize the compressor. (Correct answer)
add refrigerant to the system.

Correct answer: energize the compressor.

Energizing a compressor when a system is in a deep vacuum is extremely dangerous and can cause severe damage. Without sufficient refrigerant vapor to cool and lubricate the compressor, it can overheat, seize, or experience motor winding damage. Compressors are designed to compress vapor, not operate under vacuum conditions without proper lubrication and cooling.

Question 78: What does a star (*) stamped after the retest date on a DOT cylinder indicate?

The cylinder is certified for flammable refrigerants
The cylinder failed its last test
The cylinder qualifies for a 10-year retest interval (Correct answer)
The cylinder was manufactured to metric standards

Correct answer: The cylinder qualifies for a 10-year retest interval

A star after the retest date means the cylinder passed an enhanced test and is approved for a 10-year requalification interval instead of the standard 5 years.

Question 79: EPA Section 608 Type III certification is required for technicians servicing which type of equipment?

Motor vehicle A/C systems using R-134a
Low-pressure systems such as centrifugal chillers using R-11 or R-123 (Correct answer)
High-pressure systems such as R-410A split systems
Small appliances with hermetically sealed compressors

Correct answer: Low-pressure systems such as centrifugal chillers using R-11 or R-123

Type III certification covers low-pressure systems — large commercial and industrial chillers that use refrigerants such as R-11, R-113, and R-123 (HCFC-123). These refrigerants have saturation pressures below atmospheric pressure at normal operating temperatures, meaning the systems operate under vacuum. This unique characteristic requires special training and handling procedures.

Question 80: When evacuating a system before recharging, what is the purpose of performing a "triple evacuation" (also called "triple deep evacuation")?

To remove moisture more thoroughly by breaking vacuum with dry nitrogen between evacuation cycles (Correct answer)
To satisfy EPA requirements for systems over 200 lbs before recharging
To verify the vacuum pump is functioning at rated capacity
To achieve three times the required vacuum depth for better system performance

Correct answer: To remove moisture more thoroughly by breaking vacuum with dry nitrogen between evacuation cycles

Triple evacuation (or triple deep evacuation) involves evacuating the system, breaking the vacuum with dry nitrogen, and evacuating again — repeated three times. This process is more effective at removing moisture than a single deep evacuation because nitrogen purging carries moisture to the vacuum pump. Each evacuation cycle removes a greater percentage of remaining moisture, protecting the system from acid formation.

Question 81: When recovering refrigerant from a system with a non-condensable gas problem such as air, what is the recommended approach?

Add nitrogen to dilute the air
Vent the air directly to the atmosphere
Recover the mixture and avoid releasing the non-condensables separately into the air (Correct answer)
Increase compressor speed to push air out

Correct answer: Recover the mixture and avoid releasing the non-condensables separately into the air

Technicians should not vent non-condensables; the mixture should be handled through proper recovery and recycling equipment.

Question 82: The safest way to determine how much refrigerant is in a recovery cylinder is to:

Check the color of the cylinder
Read the pressure gauge only
Weigh the cylinder using a scale (Correct answer)
Estimate by feel

Correct answer: Weigh the cylinder using a scale

Weighing the cylinder on a scale is the accurate way to track the charge and avoid exceeding the 80% fill limit.

Question 83: When shipping a recovery cylinder of refrigerant, it must be labeled and transported in accordance with:

AHRI marketing rules
DOT hazardous materials regulations (Correct answer)
Local zoning codes
EPA Section 608 only

Correct answer: DOT hazardous materials regulations

Recovery cylinders are shipped under DOT hazardous materials regulations with proper labeling.

Question 84: When using a system-dependent recovery system on a compressor-operated appliance, the technician should:

Run the compressor and recover from the low side of the system only.
Install access fittings on both the high and low-pressure sides of the system.
Run the compressor and recover from the high side of the system only. (Correct answer)
allow the refrigerant to go to the high side of the system.

Correct answer: Run the compressor and recover from the high side of the system only.

When using a system-dependent recovery system on a compressor-operated appliance, running the compressor helps move the refrigerant from the low side to the high side. Recovering from the high side allows for more efficient removal of refrigerant, especially when the compressor can still function. This method maximizes the amount of refrigerant recovered from the system.

Question 85: What is the recovery/evacuation requirement for a small high-pressure appliance containing less than 200 lbs with a non-operating compressor (post-1993 equipment)?

4 inches Hg vacuum (Correct answer)
10 inches Hg vacuum
0 inches Hg vacuum
15 inches Hg vacuum

Correct answer: 4 inches Hg vacuum

Appliances under 200 lbs with a non-operating compressor must be evacuated to 4 inches of mercury vacuum.

Question 86: If a leak repair attempt fails verification, the owner must do which of the following?

Vent the system and abandon it
Top off the charge weekly
Conduct a follow-up verification and possibly develop a retrofit/retire plan (Correct answer)
Ignore it until next year

Correct answer: Conduct a follow-up verification and possibly develop a retrofit/retire plan

Failed repairs require follow-up verification and may require a retrofit or retirement plan.

Question 87: The ozone layer in the stratosphere extends how many miles above the Earth's surface?

31 (Correct answer)
41
45
21

Correct answer: 31

The ozone layer is a region within the Earth's stratosphere that absorbs most of the Sun's ultraviolet radiation. This vital layer is primarily located at an altitude ranging from approximately 6 to 31 miles (10 to 50 kilometers) above the Earth's surface, with the highest concentration of ozone typically found around 15-20 miles up.

Question 88: Which document proves a technician's Section 609 certification?

Driver's license
Sales receipt
Vehicle registration
EPA Section 609 certification card (Correct answer)

Correct answer: EPA Section 609 certification card

A Section 609 certification card documents the technician's qualification.

Question 89: An owner of a commercial refrigeration appliance with a full charge of 60 pounds of an ozone-depleting refrigerant discovers the annual leak rate has exceeded the acceptable threshold. According to EPA Section 608 regulations, what is the maximum time allowed to repair the leaks?

120 days
60 days
10 days
30 days (Correct answer)

Correct answer: 30 days

For commercial refrigeration appliances containing 50 or more pounds of refrigerant, the EPA requires that leaks be repaired within 30 days of discovery when the leak rate threshold is exceeded.

Question 90: EPA Section 608 Type II certification covers which category of refrigeration and air conditioning equipment?

High-pressure systems other than small appliances (Correct answer)
Low-pressure systems using refrigerants below atmospheric pressure
Small appliances with hermetically sealed compressors and less than 5 lbs of refrigerant
Motor vehicle air conditioning systems

Correct answer: High-pressure systems other than small appliances

Type II certification under EPA Section 608 covers high-pressure systems other than small appliances. This includes most commercial and industrial refrigeration equipment, large split systems, rooftop units, and other high-pressure systems that contain refrigerants such as R-22, R-410A, R-404A, and similar refrigerants that operate above atmospheric pressure.

Question 91: Why must oil drained from a recovered small appliance be handled carefully?

It is highly flammable like gasoline
It may contain dissolved refrigerant that can still vent (Correct answer)
It must be returned to the manufacturer
It is radioactive

Correct answer: It may contain dissolved refrigerant that can still vent

Used oil can hold dissolved refrigerant, so it must be handled to avoid venting and disposed of properly.

Question 92: Under the Clean Air Act, which substances are technicians prohibited from knowingly venting during the maintenance or disposal of appliances?

Only refrigerants over 50 pounds in a single system
Class I, Class II, and most non-exempt substitute refrigerants such as HFCs (Correct answer)
Only CFC and HCFC refrigerants
Only ammonia-based refrigerants

Correct answer: Class I, Class II, and most non-exempt substitute refrigerants such as HFCs

The venting prohibition covers CFCs, HCFCs, and their substitutes including HFCs, with only a few specifically exempted substances.

Question 93: Technicians who only recover refrigerant from small appliances during disposal need at minimum which certification?

Universal only
Type I (Correct answer)
Type II
Type III

Correct answer: Type I

Type I certification covers servicing and disposal of small appliances, which is where most passive small-appliance recovery occurs.

Question 94: What is the difference between recycling and reclaiming refrigerant under EPA rules?

They are identical processes
Recycling requires sending to a lab, reclaiming is done on-site
Reclaiming is illegal
Reclaiming purifies refrigerant to a strict standard, recycling only reduces contaminants (Correct answer)

Correct answer: Reclaiming purifies refrigerant to a strict standard, recycling only reduces contaminants

Reclaiming restores refrigerant to ARI-700 purity, while recycling only reduces contaminants on-site.

Question 95: The ozone depletion potential (ODP) of Class II refrigerants is less than _____ :

1.0
0.7
0.2 (Correct answer)
0.5

Correct answer: 0.2

Class II refrigerants, primarily HCFCs (hydrochlorofluorocarbons), have an ozone depletion potential (ODP) that is less than 0.2. While they still contribute to ozone depletion, their impact is significantly less than Class I refrigerants (CFCs), which have ODPs of 0.2 or higher. HCFCs are being phased out due to their remaining ODP.

Question 96: A leak detection method that uses an electronic device sensitive to halogenated refrigerants is called a:

Soap bubble test
Standing pressure test
Electronic leak detector (Correct answer)
Halide torch

Correct answer: Electronic leak detector

Electronic leak detectors sense halogenated refrigerant escaping from leaks.

Question 97: Which of the following refrigerants is chlorine-free?

CFC
HFC (Correct answer)
None of the above
HCFC

Correct answer: HFC

HFCs (hydrofluorocarbons) are chlorine-free refrigerants, meaning they do not contain chlorine atoms that deplete the ozone layer. Unlike CFCs and HCFCs, HFCs have an Ozone Depletion Potential (ODP) of zero. However, HFCs are potent greenhouse gases and are being phased down due to their high Global Warming Potential (GWP).

Question 98: What is the role of a receiver in a high-pressure refrigeration system?

To store excess liquid refrigerant and ensure a continuous supply to the expansion device (Correct answer)
To separate oil from refrigerant before it reaches the compressor
To measure refrigerant level using a float-type gauge
To remove moisture from the refrigerant using a desiccant core

Correct answer: To store excess liquid refrigerant and ensure a continuous supply to the expansion device

The receiver stores liquid refrigerant between the condenser and the expansion device. It provides a reservoir that accommodates variations in system refrigerant charge during different operating conditions (temperature, load), ensures a steady supply of liquid to the expansion device, and allows technicians to isolate refrigerant in the receiver for service via pump-down procedures.

Question 99: When recovering R-1234yf from a motor vehicle A/C system, technicians must use equipment that is:

Rated only for high-pressure refrigerants above 500 psi
Compatible with R-134a recovery machines without modification
Dedicated to R-1234yf and not cross-contaminated with other refrigerants (Correct answer)
Approved for use with both HFC and CFC refrigerants interchangeably

Correct answer: Dedicated to R-1234yf and not cross-contaminated with other refrigerants

R-1234yf requires dedicated recovery equipment because mixing it with R-134a or other refrigerants makes reclamation impossible and can create unsafe conditions. Equipment must be clearly labeled and kept separate to maintain refrigerant purity for reuse or reclamation.

Question 100: Which of the following substances is generally exempt from the venting prohibition?

R-22
R-134a
R-410A
Certain hydrocarbons and CO2 used as substitutes (Correct answer)

Correct answer: Certain hydrocarbons and CO2 used as substitutes

Some EPA-approved substitutes like CO2 are exempted from the venting prohibition, though good practice still applies.

EPA Section 608 Certification

The EPA Section 608 certification is required for technicians who maintain, service, repair, or dispose of equipment that could release refrigerants into the atmosphere.

100

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120 min

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70%

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