CFC Alternative Refrigerants & Transitions 3 — Questions and Answers
Question 1: Under the AIM Act, EPA is authorized to phase down HFCs by what maximum percentage over 15 years?
- 50%
- 65%
- 75%
- 85% (Correct answer)
Correct answer: 85%
The AIM Act authorizes EPA to reduce HFC production and consumption by 85% over 15 years from a baseline period.
Question 2: R-1234yf is primarily used as a replacement for which refrigerant in mobile air conditioning systems?
- R-22
- R-134a (Correct answer)
- R-410A
- R-12
Correct answer: R-134a
R-1234yf was developed specifically to replace R-134a in mobile air conditioning systems due to its GWP of less than 1.
Question 3: Which refrigerant blend is being widely adopted as a lower-GWP alternative to R-410A in residential heat pumps, with approximately 78% lower GWP?
- R-407C
- R-32
- R-454B (Correct answer)
- R-422D
Correct answer: R-454B
R-454B has a GWP of approximately 466 compared to R-410A's GWP of 2088, representing about a 78% reduction and making it the leading next-generation residential heat pump refrigerant.
Question 4: What safety classification applies to R-1234yf?
- A1 (non-flammable, low toxicity)
- A2L (mildly flammable, low toxicity) (Correct answer)
- B1 (non-flammable, higher toxicity)
- A3 (highly flammable, low toxicity)
Correct answer: A2L (mildly flammable, low toxicity)
R-1234yf is classified A2L by ASHRAE, meaning it has low toxicity but mild flammability requiring special handling and equipment design.
Question 5: When fractionation occurs in a zeotropic blend during a leak, what is the technician's required action?
- Top off the system with the same blend
- Recover remaining refrigerant and recharge with a full, fresh charge (Correct answer)
- Add only the component that leaked preferentially
- Switch to a different refrigerant immediately
Correct answer: Recover remaining refrigerant and recharge with a full, fresh charge
When fractionation changes the blend composition, technicians must recover the remaining refrigerant and recharge with a complete new charge to restore proper blend ratios.
Question 6: Which lubricant type is generally required for HFC refrigerants such as R-410A?
- Mineral oil (MO)
- Alkylbenzene (AB) oil
- Polyolester (POE) oil (Correct answer)
- Polyalphaolefin (PAO) oil
Correct answer: Polyolester (POE) oil
HFC refrigerants like R-410A require polyolester (POE) oil because POE is miscible with HFCs, whereas mineral oil is not.
Question 7: The Kigali Amendment to the Montreal Protocol requires developed countries to begin phasing down HFCs starting in which year?
- 2019 (Correct answer)
- 2024
- 2028
- 2032
Correct answer: 2019
Developed countries committed to begin phasing down HFC production and consumption by 10% starting in 2019 under the Kigali Amendment.
CFC Alternative Refrigerants & Transitions 3
Under the AIM Act, EPA is authorized to phase down HFCs by what maximum percentage over 15 years?