What refrigerant has a zero ozone depletion potential but is still considered a greenhouse gas?

R-134a is a refrigerant with a zero ozone depletion potential (ODP), which means it does not contribute to the degradation of the ozone layer. This characteristic is significant because the ozone layer protects the Earth from harmful ultraviolet radiation. However, it's important to note that R-134a is still considered a greenhouse gas due to its global warming potential (GWP).

Greenhouse gases trap heat in the atmosphere, contributing to climate change, and R-134a has a GWP that is substantially higher than that of carbon dioxide, even though it does not harm the ozone layer. This distinction is crucial in modern HVAC practices as regulations continue to evolve towards substances that minimize environmental impact.

Other refrigerants listed, such as R-12 or R-22, have substantial ODPs and also contribute to global warming, while R-410A, although having no ODP, still has a significant GWP. Thus, R-134a represents a balance of ozone safety and the need to be aware of greenhouse effects.