Code Treatment of A2L Refrigerants

Worldwide efforts to combat climate change have included a push to attempt to reduce the impact that refrigerants have on global warming. In an effort to shift away from widely used refrigerants that have a major global warming impact, the refrigeration industry has found that most alternative refrigerants are flammable. Some refrigeration end uses, such as small appliances with limited refrigerant charge have already transitioned to use flammable refrigerants. However, most flammable refrigerants are too flammable to be used in systems with larger capacities. One group of refrigerants that could act as a replacement is a newly classified A2L refrigerant group, which is described as “mildly flammable.” While several countries have already transitioned to using these mildly flammable refrigerants, several major obstacles remain in place for the transition to happen in the U.S.

This paper is intended to describe the current state of codes and standards as they relate to A2L refrigerants, while identifying code gaps, and providing guidance to states and model code organizations for the allowance of A2L refrigerants.