Refrigerant Types & Properties Flashcards
6 cards from real EPA 609 practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Refrigerant Types & Properties flashcards as text
Which term describes the process where a refrigerant blend separates into its component gases during a leak?
Answer: Fractionation
Fractionation occurs when blend refrigerants leak, causing components with different boiling points to escape at different rates, changing the mixture's composition.
What is the ASHRAE safety classification of R-134a?
Answer: A1 (non-toxic, non-flammable)
R-134a is classified A1 by ASHRAE, indicating it has low toxicity and is non-flammable under normal conditions.
At what temperature does R-134a become a gas in an MVAC system's evaporator?
Answer: Above its boiling point at the low-side operating pressure
Refrigerant boils and becomes a gas in the evaporator when the temperature exceeds its boiling point at the prevailing low-side pressure.
Which refrigerant has the highest ozone depletion potential (ODP) among those listed?
Answer: R-12
R-12 has an ODP of 1.0, the reference value for ozone depletion, making it the most harmful to the ozone layer of these options.
What does the term 'critical point' mean for a refrigerant?
Answer: The temperature and pressure above which liquid and vapor phases are indistinguishable
The critical point is the temperature and pressure above which a refrigerant exists as a supercritical fluid with no distinct liquid or vapor phase.
Why must refrigerant cylinders never be completely filled with liquid?
Answer: Liquid expansion from heat can cause cylinder rupture
Liquid refrigerant expands significantly with temperature increases, and a completely full cylinder can rupture catastrophically due to hydraulic pressure.