The Refrigerant Compliance Glossary

Ammonia used as a refrigerant, with zero GWP (AR4, 100-year) and zero ODP, standard in industrial refrigeration and large cold storage. It is ASHRAE class B2L — higher toxicity and mildly flammable.

Carbon dioxide used as a refrigerant, with a GWP of 1 (AR4, 100-year) and no ozone impact. Commonly deployed in transcritical systems for supermarkets and cold storage.

HFO-containing blends with GWPs near 1,390 (AR4, 100-year), widely used as R-404A replacements in supermarket and commercial refrigeration.

An A2L blend of R-32 and R-1234yf with a GWP near 466 (AR4, 100-year), adopted widely as the R-410A replacement in new AC and heat pump equipment.

A single-component A2L refrigerant with a GWP near 675 (AR4, 100-year), used in new AC and heat pump equipment as an R-410A replacement.

A single-component HFC with a GWP near 1,430 (AR4, 100-year), used in medium-temperature refrigeration, centrifugal chillers, and vehicle air conditioning.

An HFC blend with a GWP near 2,088 (AR4, 100-year), the standard for commercial and residential AC for two decades. It exceeds the 700-GWP limit for most new AC and chiller subsectors, so new equipment has moved to lower-GWP alternatives.

An HCFC refrigerant with an ODP of roughly 0.055 and a GWP near 1,810 (AR4, 100-year), long dominant in commercial AC and refrigeration. Production and import ended January 1, 2020; existing equipment may still be serviced with recovered or reclaimed stock.

The change in a zeotropic blend’s composition when one component leaks or boils off preferentially, leaving a mixture that no longer matches its specification. Capacity and pressure behavior shift with it.

The temperature spread between the start and end of a zeotropic blend’s phase change at constant pressure. Some blends glide only a degree or two; others glide five to ten.