EPA Refrigerant Types and Properties Flashcards
6 cards from real EPA practice questions. Tap to flip, then mark Knew It or Still Learning โ missed cards come back until you master them.
Read the first 6 EPA Refrigerant Types and Properties flashcards as text
What is the ASHRAE safety classification for R-717 (ammonia)?
Answer: B2L
Ammonia (R-717) is classified B2L because it is toxic (B) and mildly flammable (2L), requiring strict safety protocols in industrial refrigeration.
Which refrigerant is a natural refrigerant commonly used in low-temperature cascade refrigeration systems?
Answer: R-744 (CO2)
R-744 (carbon dioxide) is a natural refrigerant with a GWP of 1 and ODP of 0, making it environmentally favorable for use in cascade and transcritical systems.
What characteristic makes R-290 (propane) both desirable and hazardous as a refrigerant?
Answer: Excellent thermodynamic properties and high flammability
R-290 (propane) has excellent thermodynamic efficiency, zero ODP, and low GWP, but its A3 flammability classification requires strict charge limits and safety measures.
What is the purpose of a refrigerant's 'bubble point' measurement?
Answer: The point at which refrigerant starts to evaporate (all liquid)
The bubble point is the temperature at which a liquid refrigerant begins to vaporize at a given pressure, indicating the start of the evaporation process.
Which class of refrigerants is currently being promoted as long-term low-GWP replacements for HFCs?
Answer: HFOs
HFOs (hydrofluoroolefins) are being developed as next-generation refrigerants with very low GWP values (often below 10) and zero ODP.
What does a refrigerant's ASHRAE number prefix of '1' (e.g., R-134a vs. R-1234yf) indicate?
Answer: One carbon-carbon double bond (unsaturated)
The '1' prefix in ASHRAE refrigerant numbering indicates the molecule contains one carbon-carbon double bond, classifying it as an unsaturated compound (olefin/HFO).