1 Refrigerant Types and Classification Free Online FlashCards

What defines CFCs, and what is one environmental concern?

CFCs contain chlorine, fluorine, and carbon. They can deplete stratospheric ozone; R-12 is a legacy example.

What elements define HCFCs, and what is a common example?

HCFCs contain hydrogen, chlorine, fluorine, and carbon. They deplete ozone, generally less than CFCs; R-22 is an example.

What distinguishes HFCs from CFCs and HCFCs?

HFCs contain hydrogen, fluorine, and carbon but no chlorine. They do not significantly deplete ozone, though many have high GWP.

What is a characteristic of HFOs, and name one example.

HFOs are unsaturated fluorinated refrigerants. Many have lower GWP than older HFC options; R-1234yf is used in many newer vehicle air-conditioning systems.

What is a key safety tradeoff of hydrocarbon refrigerants?

Hydrocarbon refrigerants include propane and isobutane. They generally have very low GWP but are often highly flammable; R-600a is used in domestic refrigerators.

Which refrigerants are R-744 and R-717, and what hazard is notable for R-717?

R-744 is carbon dioxide, used in commercial refrigeration and heat pumps. R-717 is ammonia, used in industrial refrigeration and classified B2L, reflecting significant toxicity and lower flammability.

What can a lowercase suffix in an R-number indicate?

A trailing lowercase letter can distinguish refrigerant isomers; for example, the “a” in R-134a distinguishes an isomer.

What blend behavior is generally associated with the 400 series?

The 400 series generally identifies zeotropic blends. Their liquid and vapor compositions differ, and they can have temperature glide during boiling or condensation at constant pressure.

What behavior is associated with the 500 series?

The 500 series identifies azeotropic blends, which behave as a constant-composition mixture at a specified pressure. Check technical data for a blend’s behavior.

Why is a zeotropic blend commonly charged from the cylinder’s liquid phase?

Technicians commonly charge a zeotropic blend from the cylinder’s liquid phase, following manufacturer instructions, to reduce the risk of changing its composition.

What do the letter and number in an ASHRAE safety class indicate?

In an ASHRAE safety class, A means lower toxicity and B higher toxicity. Class 1 means no flame propagation under the specified test; 2 and 3 indicate increasing flammability categories.

How should a technician identify a refrigerant reliably?

Use the printed refrigerant designation on the equipment nameplate and cylinder label, then consult the SDS. Cylinder color alone is not a universal identification method.