Several new codes defer to IIAR when it comes to ammonia.
Several national industry code bodies have incorporated the IIAR’s safety standards into their latest updates, according to Jeffrey Shapiro, president of International Code Consultants, and the code consultant for IIAR.
Speaking at the IIAR Conference and Expo’s government affairs update last month, Shapiro said the IIAR has been successful in convincing these code organizations that ammonia should in many cases be treated differently from other refrigerants. By the end of this year, he said he hopes to have ammonia removed (by addendum) from the standard known as ASHRAE-15, prescribed by the American Society of Heating, Refrigeration and Air Conditioning Engineers.
“We've been laying the groundwork over the past several years to get out from under the umbrella of ASHRAE 15,” said Shapiro.
Among the other developments is that ammonia is now excluded entirely from the 2018 Uniform Mechanical Code, he said, because the IIAR-2 standard includes all the necessary information.
In addition, the International Fire Code (IFC) no longer references ASHRAE-15 for ammonia. One benefit of this is that users of ammonia systems will not be required to follow IFC requirements for emergency alarms and gas detection systems, which Shapiro said did not really apply to ammonia because of its unique properties. Instead, the alarm and detection issues as they relate to ammonia refrigeration are addressed in IIAR-2.
In the International Mechanical Code (IMC), Shapiro said the IIAR was successful in changing the requirements for ammonia leak detection.
The IMC has historically mandated that refrigerated process and storage areas have ammonia detection systems.This has been opposed by many in the industry who have felt it was inappropriate to require ammonia detection anywhere there was ammonia, such as cleaning areas where harsh chemicals are used, and in certain other areas. The newest version of the IMC code does not require detectors in any unoccupied pipe area without valves, in harsh environments, and in areas that are always occupied, the definition of which is left open to site-specific interpretation.
“We've been laying the groundwork over the past several years to get out from under the umbrella of ASHRAE 15."
– Jeffrey Shapiro, IIAR
IIAR was also successful in changing the IMC to allow the use of certain low-risk pumps outside of machinery rooms, and in allowing machinery rooms on process floors without direct egress to outside the building. It also changed the definition of a machinery room so that such rooms only have to meet machinery room regulations under certain conditions, not merely because of the presence of refrigeration equipment.
Another change in the IMC involves the requirements for industrial spaces that are chilled with brine as a secondary refrigerant. While previously the IMC required that such spaces be treated as industrial, even though brine does not behave like a refrigerant in terms of undergoing a phase change, the updated IMC exempts brine from these requirements.
The National Fire Protection Association’s National Electrical Code (NEC) no longer requires adequate ventilation in process and storage areas of facilities that use ammonia in order for those areas not to be considered hazardous (classified). The NEC refers users to IIAR-2, which states that ventilation is not required in process and storage areas.
Among the proposals that the IIAR is looking at for the 2021 codes is the elimination of the requirement for emergency pressure and control systems for outdoor NH3equipment. The IIAR is also proposing that operators not be required to conduct fire and environmental impact analyses for emergency releases of ammonia into the environment, as currently required. Instead they would only need to conduct a health analysis. The IIAR is also suggesting that the code not require the services of an engineer for such an analysis.
IIAR is also seeking to have the 2021 IMC put IIAR-2 on par with ASHRAE-15 for ammonia refrigeration, or to defer to IIAR-2 completely, following the example of the UMC.