HVAC - EPA Certification Practice Exam

Hydrochlorofluorocarbons (HCFCs) are a class of chemical compounds used in HVAC systems and refrigerants that have a lower ozone depletion potential compared to older compounds like chlorofluorocarbons (CFCs). R-22 is a well-known example of an HCFC and has been widely used in residential and commercial air conditioning systems. It contains chlorine, hydrogen, fluorine, and carbon, and while it poses some risk to the ozone layer, it is less damaging than its CFC predecessors. Because of their ozone-depleting properties, the use of R-22 is being phased out under international agreements like the Montreal Protocol, but it has historically been a standard refrigerant in many applications. In contrast, R-12 is a CFC, R-134a is a hydrofluorocarbon (HFC), and R-500 is a blend that includes both CFCs and HCFCs. Thus, R-22 stands out as the appropriate response in this context as an HCFC.