EPA 608 609 Refrigerant Properties and Identification 1 — Questions and Answers
Question 1: What is the ASHRAE/ARI standard cylinder color for R-22 refrigerant?
- Light blue
- Green (Correct answer)
- Rose (pink)
- Yellow
Correct answer: Green
ASHRAE/ARI assigns green as the standard cylinder color for R-22 to prevent misidentification during service.
Question 2: Which refrigerant is classified as a hydrofluorocarbon (HFC)?
- R-22
- R-12
- R-134a (Correct answer)
- R-11
Correct answer: R-134a
R-134a is an HFC (tetrafluoroethane) containing only hydrogen, fluorine, and carbon — no chlorine — giving it zero ozone depletion potential.
Question 3: What does the term 'azeotropic blend' mean when referring to refrigerants?
- A blend that separates into components during a leak
- A mixture that behaves like a single refrigerant with a constant boiling point (Correct answer)
- A refrigerant that contains no lubricating oil
- A blend approved only for commercial refrigeration
Correct answer: A mixture that behaves like a single refrigerant with a constant boiling point
An azeotropic blend maintains its composition during phase changes and boils at a constant temperature, behaving like a single-component refrigerant.
Question 4: Which of the following is a chlorofluorocarbon (CFC) refrigerant?
- R-134a
- R-410A
- R-12 (Correct answer)
- R-407C
Correct answer: R-12
R-12 (dichlorodifluoromethane) is a CFC containing only chlorine and fluorine with no hydrogen, making it highly ozone-depleting and fully phased out.
Question 5: What substance serves as the reference standard (GWP = 1) for Global Warming Potential calculations?
- Chlorine
- Carbon dioxide (CO2) (Correct answer)
- Methane
- Water vapor
Correct answer: Carbon dioxide (CO2)
CO2 has a defined GWP of 1 and serves as the baseline against which all other greenhouse gases are measured over a 100-year horizon.
Question 6: Which refrigerant blend is classified as zeotropic (near-azeotropic)?
- R-500
- R-502
- R-407C (Correct answer)
- R-507A
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 7: What ozone depletion potential (ODP) does R-134a have?
- 1.0
- 0.055
- 0.50
- 0 (Correct answer)
Correct answer: 0
R-134a has an ODP of zero because it contains no chlorine or bromine atoms — the elements responsible for destroying stratospheric ozone.
EPA 608 609 Refrigerant Properties and Identification 1
What is the ASHRAE/ARI standard cylinder color for R-22 refrigerant?