ASE AC 609 Certification Exam – Verified
Questions & Answers 2026 | Graded A+ Study
Guide
ASE AC 609 CERTIFICATION EXAM – VERIFIED QUESTIONS & ANSWERS 2026
Graded A+ Study Guide | 300 Questions
1. Which refrigerant was most commonly used in automotive air conditioning
systems before being phased out due to ozone depletion?
A. R-134a
B. R-1234yf
C. R-22
D. R-12
E. R-410A
CORRECT ANSWER: D. R-12
RATIONALE: R-12 (dichlorodifluoromethane), a chlorofluorocarbon (CFC), was
the standard refrigerant in automotive AC systems for decades. It was phased out under
the Montreal Protocol due to its high ozone depletion potential (ODP) of 1.0.
2. What is the ASHRAE-assigned color for R-134a refrigerant cylinders?
A. White
B. Rose/Pink
C. Light Green
, D. Orange
E. Light Blue
CORRECT ANSWER: E. Light Blue
RATIONALE: According to ASHRAE Standard 34, R-134a is assigned the color
light blue (sky blue) for cylinder identification. R-12 is white, R-22 is light green, and R-
410A is rose/pink.
3. What type of refrigerant is R-1234yf?
A. Chlorofluorocarbon (CFC)
B. Hydrochlorofluorocarbon (HCFC)
C. Hydrofluorocarbon (HFC)
D. Hydrofluoroolefin (HFO)
E. Perfluorocarbon (PFC)
CORRECT ANSWER: D. Hydrofluoroolefin (HFO)
RATIONALE: R-1234yf is a hydrofluoroolefin (HFO) refrigerant. It has a global
warming potential (GWP) of only 4 and zero ozone depletion potential, making it the
preferred modern automotive refrigerant under new regulations.
4. What is the Global Warming Potential (GWP) of R-134a?
A. 1
B. 4
, C. 1,430
D. 10,900
E. 2,090
CORRECT ANSWER: C. 1,430
RATIONALE: R-134a has a GWP of 1,430, meaning it is 1,430 times more potent
as a greenhouse gas than carbon dioxide over a 100-year period. This is why the
automotive industry transitioned to R-1234yf, which has a GWP of only 4.
5. What is the Ozone Depletion Potential (ODP) of R-134a?
A. 0
B. 0.5
C. 1.0
D. 1.5
E. 2.0
CORRECT ANSWER: A. 0
RATIONALE: R-134a is a hydrofluorocarbon (HFC) and contains no chlorine
atoms, giving it an ozone depletion potential of zero. However, it does contribute
significantly to global warming due to its high GWP of 1,430.
6. What is the GWP of R-1234yf?
A. 1,430
, B. 10,900
C. 22
D. 4
E. 0
CORRECT ANSWER: D. 4
RATIONALE: R-1234yf has an extremely low GWP of approximately 4, which
makes it nearly 99.7% less harmful to the climate than R-134a. This low GWP is one of
the primary reasons for its adoption as the replacement for R-134a in modern vehicles.
7. R-12 refrigerant belongs to which chemical family?
A. HFC
B. HFO
C. CFC
D. HCFC
E. PFC
CORRECT ANSWER: C. CFC
RATIONALE: R-12 is a chlorofluorocarbon (CFC). CFCs contain chlorine, fluorine,
and carbon. The chlorine atoms are responsible for catalytically destroying stratospheric
ozone, making CFCs the most harmful refrigerants to the ozone layer.
Questions & Answers 2026 | Graded A+ Study
Guide
ASE AC 609 CERTIFICATION EXAM – VERIFIED QUESTIONS & ANSWERS 2026
Graded A+ Study Guide | 300 Questions
1. Which refrigerant was most commonly used in automotive air conditioning
systems before being phased out due to ozone depletion?
A. R-134a
B. R-1234yf
C. R-22
D. R-12
E. R-410A
CORRECT ANSWER: D. R-12
RATIONALE: R-12 (dichlorodifluoromethane), a chlorofluorocarbon (CFC), was
the standard refrigerant in automotive AC systems for decades. It was phased out under
the Montreal Protocol due to its high ozone depletion potential (ODP) of 1.0.
2. What is the ASHRAE-assigned color for R-134a refrigerant cylinders?
A. White
B. Rose/Pink
C. Light Green
, D. Orange
E. Light Blue
CORRECT ANSWER: E. Light Blue
RATIONALE: According to ASHRAE Standard 34, R-134a is assigned the color
light blue (sky blue) for cylinder identification. R-12 is white, R-22 is light green, and R-
410A is rose/pink.
3. What type of refrigerant is R-1234yf?
A. Chlorofluorocarbon (CFC)
B. Hydrochlorofluorocarbon (HCFC)
C. Hydrofluorocarbon (HFC)
D. Hydrofluoroolefin (HFO)
E. Perfluorocarbon (PFC)
CORRECT ANSWER: D. Hydrofluoroolefin (HFO)
RATIONALE: R-1234yf is a hydrofluoroolefin (HFO) refrigerant. It has a global
warming potential (GWP) of only 4 and zero ozone depletion potential, making it the
preferred modern automotive refrigerant under new regulations.
4. What is the Global Warming Potential (GWP) of R-134a?
A. 1
B. 4
, C. 1,430
D. 10,900
E. 2,090
CORRECT ANSWER: C. 1,430
RATIONALE: R-134a has a GWP of 1,430, meaning it is 1,430 times more potent
as a greenhouse gas than carbon dioxide over a 100-year period. This is why the
automotive industry transitioned to R-1234yf, which has a GWP of only 4.
5. What is the Ozone Depletion Potential (ODP) of R-134a?
A. 0
B. 0.5
C. 1.0
D. 1.5
E. 2.0
CORRECT ANSWER: A. 0
RATIONALE: R-134a is a hydrofluorocarbon (HFC) and contains no chlorine
atoms, giving it an ozone depletion potential of zero. However, it does contribute
significantly to global warming due to its high GWP of 1,430.
6. What is the GWP of R-1234yf?
A. 1,430
, B. 10,900
C. 22
D. 4
E. 0
CORRECT ANSWER: D. 4
RATIONALE: R-1234yf has an extremely low GWP of approximately 4, which
makes it nearly 99.7% less harmful to the climate than R-134a. This low GWP is one of
the primary reasons for its adoption as the replacement for R-134a in modern vehicles.
7. R-12 refrigerant belongs to which chemical family?
A. HFC
B. HFO
C. CFC
D. HCFC
E. PFC
CORRECT ANSWER: C. CFC
RATIONALE: R-12 is a chlorofluorocarbon (CFC). CFCs contain chlorine, fluorine,
and carbon. The chlorine atoms are responsible for catalytically destroying stratospheric
ozone, making CFCs the most harmful refrigerants to the ozone layer.
