Ammonia Code Updates

In one of the online sessions, Jeffrey M. Shapiro, P.E., FSFPE, president of International Code Consultants in Austin, Texas, offered an overview of the fire, building, and mechanical code regulations for ammonia refrigeration, including updates from the latest development cycles for the Uniform and International Codes, which will appear in the 2021 code editions.

Shapiro noted that the 2021 model codes are now finished, including the ICC [International Code Council], NFPA [National Fire Protection Association], and IAPMO [International Association of Plumbing and Mechanical Officials], which have all been completed with respect to ammonia refrigeration requirements. The 2021 UMC [Uniform Mechanical Code] is also published and available online, while the IFC [International Fire Code] and IBC [International Building Code] are still pending.

“We've made a lot of progress in having model codes and standards defer to IIAR documents for regulating ammonia refrigeration,” he said. “The 2021 NFPA 1 Code in chapter 53, which is mechanical refrigeration, will include a new section 53.1.1.3 that states, ‘ammonia refrigeration systems shall be exempt from the requirements of this chapter other than 53.1.2 and 53.1.3.’ Everything else applicable to mechanical refrigeration will regulate all other aspects of refrigeration but not ammonia refrigeration.”

Shapiro noted that the already published 2021 International Mechanical Code (IMC) includes a new section, 1101.1.2, which states that ‘refrigeration systems using ammonia as a refrigerant shall comply with IIAR 2, 3, 4, and 5 and shall not be required to comply with this chapter.” This is another very clear deferral that all the regulations applicable to refrigerants other than ammonia are still in place in this chapter, he said.

In addition, the 2021 UMC’s section 1102.2 states that “refrigeration systems using ammonia refrigerant have to comply with IIAR 2, 3, and 4 and shall not be required to comply with this chapter.”

“The latest edition of ASHRAE Standard 15-2019, Safety Standard for Refrigeration Systems, includes a section on the scope of the standard, stating that it shall not apply to refrigeration systems using ammonia,” he said. “It includes an informative note sending users to IIAR 2 [American National Standard for Safe Design of Closed-Circuit Ammonia Refrigeration Systems], so we're officially out of ASHRAE Standard 15.”

The last puzzle piece is the IFC, said Shapiro, which references IIAR standards but includes additional overlapping requirements, such as emergency shutoffs, ventilation controls, emergency pressure control systems, and refrigerant discharge and treatment.

“We did make progress in the 2021 edition of the IFC, though,” he said. “We used to be under ASHRAE 15 in the IFC, where we had to comply with ASHRAE 15 and IIAR 2 for ammonia. We've been successful at changing the IFC to now reference ASHRAE 15 for everything other than ammonia and IIAR 2 for ammonia systems. We also made progress in reducing the requirements for emergency pressure control systems. We now only require those systems for machine rooms.”

The publishing of the 2021 codes means that the new code development cycle for the 2024 editions is now underway.

“There are cycles that we follow for the NFPA and UMC, and there's a parallel cycle that runs for the international fire, building, and mechanical codes,” said Shapiro. “We are right at the beginning of the process of developing proposals to all those documents. The official ICC committees are already working on developing proposals to be submitted by the January 21 deadline, which will be all of those items that can be considered for the 2024 editions of the international codes.”

For the 2024 cycle, Shapiro is working on a proposal to remove the ammonia refrigeration regulations from the IFC. If successful, that would include language to entirely defer to IIAR standards for ammonia refrigeration.

“My opinion is the IFC is the heaviest lift of all the model codes that we've done,” he said. “But now we are 100 percent complete on all other model codes and ASHRAE 15, which gives us a very good position to argue our point that if  all other codes are willing to defer IIAR standards, so, too, should the IFC.”

A2L Code Updates

Shapiro also offered an update on A2L refrigerants, which are mildly flammable refrigerants that require changes to codes before they can be legally used in many air conditioning and refrigeration applications.

“There's been a huge battle in ASHRAE and the model codes and even at the state adoption level, legislatively and regulatorily, with A2L refrigerants,” he said. “There are some industry groups that are strongly advocating the expanded allowance of A2L refrigerants, because they make those refrigerants. There are other industry groups that are pinning their hopes on the ability to develop and promulgate refrigerants that can still meet the no-flame propagation, A1 level, that has traditionally been the HFC/HCFCs that were not good for the environment, but from a flammability perspective, work well in model codes.”

Shapiro explained that ASHRAE Standard 15-2019 recognizes A2L refrigerants for industrial applications and human comfort, but that is not the case in the uniform and international codes. In the model codes, machinery room applications were approved, but all of the proposals to expand the model codes to allow for human comfort have not been approved.

“The bottom line is that even though ASHRAE 15 currently allows for human comfort and refrigeration systems with A2L refrigerants, and UL has published the standard 60335-2-40 that will permit this, the model codes do not recognize A2L refrigerants for that application,” he said.

The battle now moves to the states, with California already establishing a special committee that will look at whether the state may amend the requirements in the model codes that prohibit A2Ls for human comfort or whether they will follow the model code requirements for some additional period of time, said Shapiro.

“Suffice it to say, there is a huge amount of industry interest, industry infighting, and lobbying,” he said. “It is an all-out battle between the different players in the non-ammonia industry that are trying to get A2L refrigerants for refrigeration and air conditioning to be acceptable.”