By now, all ASA members in the HVAC sector should be up to date on the transition to low-global Warming Potential (LGWP) refrigerants.

The federal AIM Act requires an 85% phasedown of HFC refrigerants by 2036. Many states have already updated their building codes to allow for the use of LGWP refrigerants, such as A2L, while other states, such as California, have set specific timelines for compliance.

The California Air Resource Board (CARB) has set the following prohibition timelines associated with refrigerants with a GWP of 750 or greater:

  • January 2, 2023 Room/wall/widow air-conditioning equipment, PTACs, PTHPs, portable air-conditioning equipment, and residential dehumidifiers (new)
  • January 1, 2025 Other air-conditioning (new) equipment, residential and non-residential
  • January 1, 2026 Variable Refrigerant Flow (VRF) system (new)

As mentioned in previous articles, ASA and HARDI, along with other refrigerant industry trade associations, worked diligently over the last several years in ensuring the national model codes adopted by states have been updated to address the use, transport and storage of the LGWP refrigerants such as A2L refrigerants.

The 2024 versions of the International Code Council’s building, fire and mechanical model codes and the International Association of Plumbing and Mechanical Officials mechanical model code will include revisions specifically related to the safe storage, transportation and use of A2L refrigerants. The IAPMO 2024 Uniform Mechanical Code has been published and the ICC model codes are due for publication prior to the end of 2023.

Unfortunately, the state and local adoption of the model codes into regulation often lags the most current version of the model codes published. In addition, we should anticipate that the local code officials dealing with building, fire and maintenance codes might not yet be fully up to speed on the new 2024 model code requirements.

The good news is, ICC along with AHRI, have done some excellent work in preparing code officials on the upcoming transition and changes to the model codes. I am drawing your attention to these resources, so you have them available when you are working with a local code official concerning the use of A2L refrigerants in your facilities.

The most important model code impacting distributors is the International Fire Code which defines the maximum allowable quantities of flammable gases that can be stored per control area. A2L refrigerants are classified as a low-flammability gas. The ICC, in collaboration with the Air-Conditioning, Heating and Refrigeration Institute (AHRI), have put together a webpage on the ICC site titled, Preparing for A2L Refrigerants. The website provides code officials the information they need to update their state or local codes, no matter what edition of the I-Codes they are currently using, to incorporate the required changes to facilitate compliance with the 2024 I-Code requirements associated with the transitioning to lower-GWP refrigerants, such as A2Ls.

HVAC distributors should become familiar with this website and refer code officials to this website when they have questions concerning the acceptability and storage requirements associated with A2L refrigerants. Being able to site a specific ICC source for information will provide the code officials with the confidence to adopt the needed changes.

A second resource is the AHRI Safe Transition Refrigerant Transition Task Force web page. This web page has been in existence for some time and kept up to date related to transition news. It is an excellent resource, providing background on the issue, research conducted on the safe use of A2L refrigerants and other excellent technical information. Code officials who may just now becoming aware of the transition to A2L refrigerants will find this webpage useful to better understanding the technical aspects of A2L refrigerants, along with the extensive research used in developing the 2024 adopted model code changes.

It is up to you to be knowledgeable in this area so you can have productive conversations with the local code officials in your market areas that result in a smooth transition to the storage and use of A2L refrigerants in your facilities.

I hope the two resources referenced in this article provide you with the background and support needed to ensure the efficient transition to A2Ls and acceptance by local code officials.

As always, never hesitate to reach out to me with questions or if I can be of assistance in working with your local code officials. My email address is