EPA 608 HVAC Certification Exam Prep – Real Practice Questions,
Answers & Detailed Rationales (Updated 2026) | Core, Type I,
Type II & Type III Review, Refrigerant Recovery & Recycling, Leak
Detection & Repair, System Evacuation & Charging, Refrigeration Cycle
Operations, EPA Regulations & Clean Air Act, HVAC Safety &
Environmental Compliance
Question 1: Which section of the Clean Air Act establishes the National Recycling
and Emission Reduction Program for refrigerants?
A. Section 605
B. Section 608
C. Section 612
D. Section 620
CORRECT ANSWER: B. Section 608
Rationale: Section 608 of the Clean Air Act (40 CFR Part 82, Subpart F) establishes the
National Recycling and Emission Reduction Program, which regulates refrigerant
handling, recovery, and recycling to prevent ozone-depleting substances from being
released into the atmosphere.
Question 2: What is the minimum passing score required on EPA 608 certification
examinations?
A. 60%
B. 65%
C. 70%
D. 75%
CORRECT ANSWER: C. 70%
Rationale: EPA regulations require a minimum passing score of 70% on all Section 608
certification examinations, including the Core section and each Type-specific section (I,
II, or III).
Question 3: Which refrigerant classification indicates a mildly flammable
refrigerant with low burning velocity?
A. A1
B. A2
C. A2L
D. A3
CORRECT ANSWER: C. A2L
Rationale: A2L refrigerants are classified as mildly flammable with low burning velocity
and low heat of combustion. Examples include R-454B and R-32, which are increasingly
used as lower-GWP replacements for R-410A under the AIM Act.
,Question 4: What is the primary environmental concern associated with CFC
refrigerants?
A. Global warming potential
B. Ozone depletion potential
C. Toxicity to humans
D. Flammability risk
CORRECT ANSWER: B. Ozone depletion potential
Rationale: CFC refrigerants contain chlorine atoms that, when released into the
stratosphere, catalyze the destruction of ozone molecules. A single chlorine atom can
destroy thousands of ozone molecules, significantly depleting the protective ozone
layer.
Question 5: Which type of EPA 608 certification is required to service a residential
split-system air conditioner using R-410A?
A. Type I
B. Type II
C. Type III
D. Universal only
CORRECT ANSWER: B. Type II
Rationale: Type II certification is required for servicing high-pressure appliances, which
include residential and commercial air conditioning systems using refrigerants like R-
410A, R-22, and R-134a with charges exceeding 5 pounds.
Question 6: What is the maximum allowable leak rate for comfort cooling systems
containing 50 or more pounds of refrigerant under current EPA regulations?
A. 10% annually
B. 15% annually
C. 20% annually
D. 30% annually
CORRECT ANSWER: A. 10% annually
Rationale: Under updated EPA Section 608 regulations, comfort cooling systems
containing 50 or more pounds of refrigerant must be repaired if the leak rate exceeds
10% of the total charge per year. This threshold was lowered from 15% to strengthen
leak repair requirements.
Question 7: Which recovery method is preferred when recovering refrigerant from a
system with a large liquid charge?
A. Vapor recovery only
B. Liquid recovery followed by vapor recovery
,C. Vapor recovery followed by liquid recovery
D. Passive recovery only
CORRECT ANSWER: B. Liquid recovery followed by vapor recovery
Rationale: Recovering liquid refrigerant first significantly speeds up the recovery
process because liquid occupies much less volume than vapor. After liquid is removed,
vapor recovery is performed to evacuate remaining refrigerant from the system.
Question 8: What is the primary purpose of a recovery cylinder's tare weight?
A. To determine the maximum refrigerant capacity
B. To calculate the net weight of recovered refrigerant
C. To identify the cylinder's service pressure rating
D. To verify the cylinder's hydrostatic test date
CORRECT ANSWER: B. To calculate the net weight of recovered refrigerant
Rationale: The tare weight is the empty weight of the recovery cylinder. Subtracting the
tare weight from the gross weight (cylinder plus refrigerant) gives the net weight of
recovered refrigerant, which is essential for proper documentation and preventing
overfilling.
Question 9: Which refrigerant is classified as a low-pressure refrigerant commonly
used in centrifugal chillers?
A. R-134a
B. R-410A
C. R-123
D. R-22
CORRECT ANSWER: C. R-123
Rationale: R-123 is a low-pressure HCFC refrigerant commonly used in centrifugal
chillers. Low-pressure systems operate below atmospheric pressure, requiring Type III
certification for servicing and specialized recovery procedures.
Question 10: What is the required evacuation level for a high-pressure system
containing less than 200 pounds of refrigerant when using recovery equipment
manufactured after November 15, 1993?
A. 0 psig
B. 4 inches of Hg vacuum
C. 10 inches of Hg vacuum
D. 0 microns
CORRECT ANSWER: B. 4 inches of Hg vacuum
Rationale: For high-pressure systems with less than 200 pounds of refrigerant, EPA
regulations require evacuation to 4 inches of Hg vacuum when using recovery
, equipment manufactured after November 15, 1993. Systems with 200+ pounds require
10 inches of Hg vacuum.
Question 11: Which of the following is NOT a requirement for refrigerant recovery
cylinders?
A. DOT-approved labeling
B. Color-coded yellow and gray
C. Hydrostatic testing every 5 years
D. Maximum fill level of 80% by weight
CORRECT ANSWER: B. Color-coded yellow and gray
Rationale: While recovery cylinders must be DOT-approved, hydrostatically tested
every 5 years, and filled to no more than 80% capacity by weight, there is no EPA
requirement for specific color-coding. Yellow and gray is common industry practice but
not federally mandated.
Question 12: What is the primary function of a purge unit on a low-pressure
refrigeration system?
A. To recover refrigerant during service
B. To remove non-condensable gases and moisture
C. To increase system efficiency during operation
D. To detect refrigerant leaks automatically
CORRECT ANSWER: B. To remove non-condensable gases and moisture
Rationale: Low-pressure systems operate below atmospheric pressure, allowing air
and moisture to enter through leaks. A purge unit removes these non-condensables
from the top of the condenser to maintain system efficiency and prevent corrosion.
Question 13: Which refrigerant oil is most commonly used with HFC refrigerants
like R-134a and R-410A?
A. Mineral oil
B. Alkylbenzene oil
C. Polyolester (POE) oil
D. Polyalkylene glycol (PAG) oil
CORRECT ANSWER: C. Polyolester (POE) oil
Rationale: HFC refrigerants are not miscible with traditional mineral oils. Polyolester
(POE) oil is synthetic and miscible with HFCs, making it the standard lubricant for
systems using R-134a, R-410A, and other HFC refrigerants.
Question 14: What does the term "reclaiming" mean in EPA refrigerant
management terminology?
A. Recovering refrigerant from a system for reuse in the same system
B. Processing recovered refrigerant to meet ARI-700 purity standards
Answers & Detailed Rationales (Updated 2026) | Core, Type I,
Type II & Type III Review, Refrigerant Recovery & Recycling, Leak
Detection & Repair, System Evacuation & Charging, Refrigeration Cycle
Operations, EPA Regulations & Clean Air Act, HVAC Safety &
Environmental Compliance
Question 1: Which section of the Clean Air Act establishes the National Recycling
and Emission Reduction Program for refrigerants?
A. Section 605
B. Section 608
C. Section 612
D. Section 620
CORRECT ANSWER: B. Section 608
Rationale: Section 608 of the Clean Air Act (40 CFR Part 82, Subpart F) establishes the
National Recycling and Emission Reduction Program, which regulates refrigerant
handling, recovery, and recycling to prevent ozone-depleting substances from being
released into the atmosphere.
Question 2: What is the minimum passing score required on EPA 608 certification
examinations?
A. 60%
B. 65%
C. 70%
D. 75%
CORRECT ANSWER: C. 70%
Rationale: EPA regulations require a minimum passing score of 70% on all Section 608
certification examinations, including the Core section and each Type-specific section (I,
II, or III).
Question 3: Which refrigerant classification indicates a mildly flammable
refrigerant with low burning velocity?
A. A1
B. A2
C. A2L
D. A3
CORRECT ANSWER: C. A2L
Rationale: A2L refrigerants are classified as mildly flammable with low burning velocity
and low heat of combustion. Examples include R-454B and R-32, which are increasingly
used as lower-GWP replacements for R-410A under the AIM Act.
,Question 4: What is the primary environmental concern associated with CFC
refrigerants?
A. Global warming potential
B. Ozone depletion potential
C. Toxicity to humans
D. Flammability risk
CORRECT ANSWER: B. Ozone depletion potential
Rationale: CFC refrigerants contain chlorine atoms that, when released into the
stratosphere, catalyze the destruction of ozone molecules. A single chlorine atom can
destroy thousands of ozone molecules, significantly depleting the protective ozone
layer.
Question 5: Which type of EPA 608 certification is required to service a residential
split-system air conditioner using R-410A?
A. Type I
B. Type II
C. Type III
D. Universal only
CORRECT ANSWER: B. Type II
Rationale: Type II certification is required for servicing high-pressure appliances, which
include residential and commercial air conditioning systems using refrigerants like R-
410A, R-22, and R-134a with charges exceeding 5 pounds.
Question 6: What is the maximum allowable leak rate for comfort cooling systems
containing 50 or more pounds of refrigerant under current EPA regulations?
A. 10% annually
B. 15% annually
C. 20% annually
D. 30% annually
CORRECT ANSWER: A. 10% annually
Rationale: Under updated EPA Section 608 regulations, comfort cooling systems
containing 50 or more pounds of refrigerant must be repaired if the leak rate exceeds
10% of the total charge per year. This threshold was lowered from 15% to strengthen
leak repair requirements.
Question 7: Which recovery method is preferred when recovering refrigerant from a
system with a large liquid charge?
A. Vapor recovery only
B. Liquid recovery followed by vapor recovery
,C. Vapor recovery followed by liquid recovery
D. Passive recovery only
CORRECT ANSWER: B. Liquid recovery followed by vapor recovery
Rationale: Recovering liquid refrigerant first significantly speeds up the recovery
process because liquid occupies much less volume than vapor. After liquid is removed,
vapor recovery is performed to evacuate remaining refrigerant from the system.
Question 8: What is the primary purpose of a recovery cylinder's tare weight?
A. To determine the maximum refrigerant capacity
B. To calculate the net weight of recovered refrigerant
C. To identify the cylinder's service pressure rating
D. To verify the cylinder's hydrostatic test date
CORRECT ANSWER: B. To calculate the net weight of recovered refrigerant
Rationale: The tare weight is the empty weight of the recovery cylinder. Subtracting the
tare weight from the gross weight (cylinder plus refrigerant) gives the net weight of
recovered refrigerant, which is essential for proper documentation and preventing
overfilling.
Question 9: Which refrigerant is classified as a low-pressure refrigerant commonly
used in centrifugal chillers?
A. R-134a
B. R-410A
C. R-123
D. R-22
CORRECT ANSWER: C. R-123
Rationale: R-123 is a low-pressure HCFC refrigerant commonly used in centrifugal
chillers. Low-pressure systems operate below atmospheric pressure, requiring Type III
certification for servicing and specialized recovery procedures.
Question 10: What is the required evacuation level for a high-pressure system
containing less than 200 pounds of refrigerant when using recovery equipment
manufactured after November 15, 1993?
A. 0 psig
B. 4 inches of Hg vacuum
C. 10 inches of Hg vacuum
D. 0 microns
CORRECT ANSWER: B. 4 inches of Hg vacuum
Rationale: For high-pressure systems with less than 200 pounds of refrigerant, EPA
regulations require evacuation to 4 inches of Hg vacuum when using recovery
, equipment manufactured after November 15, 1993. Systems with 200+ pounds require
10 inches of Hg vacuum.
Question 11: Which of the following is NOT a requirement for refrigerant recovery
cylinders?
A. DOT-approved labeling
B. Color-coded yellow and gray
C. Hydrostatic testing every 5 years
D. Maximum fill level of 80% by weight
CORRECT ANSWER: B. Color-coded yellow and gray
Rationale: While recovery cylinders must be DOT-approved, hydrostatically tested
every 5 years, and filled to no more than 80% capacity by weight, there is no EPA
requirement for specific color-coding. Yellow and gray is common industry practice but
not federally mandated.
Question 12: What is the primary function of a purge unit on a low-pressure
refrigeration system?
A. To recover refrigerant during service
B. To remove non-condensable gases and moisture
C. To increase system efficiency during operation
D. To detect refrigerant leaks automatically
CORRECT ANSWER: B. To remove non-condensable gases and moisture
Rationale: Low-pressure systems operate below atmospheric pressure, allowing air
and moisture to enter through leaks. A purge unit removes these non-condensables
from the top of the condenser to maintain system efficiency and prevent corrosion.
Question 13: Which refrigerant oil is most commonly used with HFC refrigerants
like R-134a and R-410A?
A. Mineral oil
B. Alkylbenzene oil
C. Polyolester (POE) oil
D. Polyalkylene glycol (PAG) oil
CORRECT ANSWER: C. Polyolester (POE) oil
Rationale: HFC refrigerants are not miscible with traditional mineral oils. Polyolester
(POE) oil is synthetic and miscible with HFCs, making it the standard lubricant for
systems using R-134a, R-410A, and other HFC refrigerants.
Question 14: What does the term "reclaiming" mean in EPA refrigerant
management terminology?
A. Recovering refrigerant from a system for reuse in the same system
B. Processing recovered refrigerant to meet ARI-700 purity standards
