A lot has happened since 2019. IIAR, in its continuing mission to promote the safe and sustainable use of natural refrigerants, produced the ANSI/IIAR CO2-2021 Safety Standard for Closed-Circuit Carbon Dioxide Refrigeration Systems. As the phase-down of F-gas refrigerants continues to accelerate worldwide, CO2 technology has become an increasingly popular option utilized in the industrial refrigeration sector and more recently in the commercial refrigeration sector.

The ANSI-approved IIAR CO2 standard specifies minimum requirements for the safe design, installation, startup, inspection, testing, and maintenance (ITM) of closed-circuit carbon refrigeration systems and for any modifications or additions to an existing system.

IIAR recently presented the latest natural refrigerants codes and standards progress update at the North American Sustainability Refrigeration Council (NARSC) Codes and Standards Progress Meeting on December 7th, 2022.

Ammonia (NH3) (R-717) is SNAP (Significant New Alternative Policy) approved. The IIAR Suite of Standards for CloseCircuit Ammonia Refrigeration Systems (C-C ARSs) consists of the following
nine (9) standards:

• IIAR 1 – Definitions & TerminologyUsed in IIAR Standards
• IIAR 2 – Design of Safe C-C ARSs
• IIAR 3 – Ammonia Refrigeration Valves
• IIAR 4 – Installation of C-C ARSs
• IIAR 5 – Startup of C-C ARSs
• IIAR 6 – Inspection, Testing, and Maintenance of C-C ARSs
• IIAR 7 – Developing Operating Procedures for C-C ARSs
•  IIAR 8 – Decommissioning of C-C ARSs
•  IIAR 9 – Minimum System SafetyRequirements for Existing C-C ARSs

CARBON DIOXIDE (CO2)(R-744) IS SNAP APPROVED.

CO2 and Ammonia standards provide equipment Safety, Engineering, Service, and meet Building Codes.

As the phase-down of F-gas refrigerants continues to accelerate worldwide, CO2 technology has become an increasingly popular option utilized in the industrial refrigeration sector and more recently in the commercial refrigeration sector.

Hydrocarbons (HCs) are in the process of being SNAP approved.

For Propane (R290), the charge limit was 150 grams per circuit.

In 2019, the IEC 60335-2-89 standard was updated to allow 500 grams
per circuit.
In 2021, the UL 60335-2-89 standard was updated to the following:

•  300 grams per circuit for closed appliances (cases with doors), and
• 500 grams per circuit for open appliances (open cases).

For HCs up to 500 grams per circuit, the HCs standards have Equipment Safety and Engineering addressed. Service is being addressed by Contractors and Service Technician Groups.

IIAR is presently developing an IIAR HC Safety Standard which is anticipated to be finalized in 2023. The IIAR HC Standard in Development is presently titled “Safety Standard for Closed-Circuit Refrigeration Systems Using Hydrocarbon Refrigerants”. This standard will address Equipment Safety and Engineering, as well as, Service. Once this standard is finished and ANSI approved, it is targeted to become presented and adopted by Building Codes.

Be aware that SNAP approvals are “Application” specific as it pertains to Refrigeration and Air Conditioning for Chillers, Cold Storage Warehouses, Ice Skating Rinks, and Industrials Processes
of Air Conditioning and Refrigeration, as well as, Retail Food Refrigeration as shown.

Hydrocarbon standards as the primary refrigerant in Cascade Systems and/or as Secondary Fluid Systems are SNAP Approved and cover Equipment Safety and Engineering. The IIAR HC Standard
in Development will address the Service and adoption by Building Codes.

SNAP (SIGNIFICANT NEW ALTERNATIVES POLICY):

Be aware that SNAP approvals are “Application” specific as it pertains to Refrigeration and Air Conditioning for Chillers, Cold Storage Warehouses, Ice Skating Rinks, and Industrials Processes of Air
Conditioning and Refrigeration, as well as, Retail Food Refrigeration as shown.

CO2:

The ANSI/IIAR CO2-2021 Standard is a companion with ASHRAE 15. ASHRAE 15 covers general design for CO2 systems.

The ANSI/IIAR CO2-2021 Standard covers general design and further covers specific minimum design requirements. And as mentioned earlier, the ANSI/ IIAR CO2-2021 standard, along with
covering general and specific design, further covers installation, startup, inspection, testing, and maintenance (ITM Tasks) for closed-circuit carbon dioxide refrigeration systems.

CO2 Occupancies:

• Public Assembly, Commercial, Residential, and Large MercantileOccupancies
• Industrial Occupancies and Refrigerated Spaces
• Walk in Coolers, Freezers, & Refrigerated Cases
• Institutional and Residential Occupancies

AMMONIA:

Also as listed earlier in this article, the IIAR Suite of Standards for Ammonia cover design, installation, startup, and inspection, testing, and maintenance (ITM Tasks) for closed-circuit ammonia refrigeration systems in separate, but harmonizing, ammonia standards.

Ammonia Occupancies:

•  Public Assembly, Commercial, Residential, and Large Mercantile Occupancies
•  Industrial Occupancies

HYDROCARBONS:

The IIAR HC Standard in Development will cover design, installation, startup, and inspection, testing, and maintenance (ITM Tasks) for closed-circuit refrigeration systems utilizing (natural)
hydrocarbon refrigerants.

Hydrocarbon Occupancies:

• Industrial Occupancies
•  Commercial Occupancies

The IIAR HC Standard in Development specifically applies to the following hydrocarbon refrigerants with a Global Warming Potential (GWP) of less than 5:

1. Propane (R290)
2. N-Butane (R600)
3. Iso-butane (R600a)

The following hydrocarbon refrigerants are reserved for future revisions.

1. Propylene (R1270)
2. Ethane (R170)
3. Ethylene (R1150)

A Refrigeration Restriction for the total of all hydrocarbons on site shall not exceed 1,100 pounds (499 kg) except where approved by the Authority Having Jurisdiction (AHJ).

PURPOSE AND SCOPE:

The ANSI-approved IIAR Suite of Standards for Ammonia, The IIAR CO2 Standard, as well as the IIAR HC Standard in Development each have a Purpose and a Scope. The Scope includes what the standards apply to, as well as, what the standard does not apply to be clear on what is not covered.

For example, The ANSI/IIAR CO2- 2021 does not cover listed equipment or systems. The intent of the standard is not to exempt an entire system based on the listing of individual components
used in that system. The standard can use listed equipment and components to design and install a large system that is covered under their individual listing standards (e.g., UL), but the entire large system is covered under the standard itself. In other words, the standard covers the entire system, and the individual listed components where used are addressed with their listing standard
requirements.

IIAR Standards are adopted by Model Codes during each of their cycles.

The following are considered as Building Codes that adopt IIAR Standards

•  International Fire Code (IFC)
•  International Mechanical Code (IMC)
• Uniform Mechanical Code (UMC)
•  National Fire Protection Association
  (NFPA):
  • NFPA 1 Fire Code
  • NFPA 70 National
    Electrical Code (NEC)

The next adoption cycle for the NFPA 70 NEC is 2023.

The next adoption cycle for the IFC, IMC, UMC, and the NFPA 1 Fire Code is 2024.

The model codes refer to IIAR for the standards that have been adopted.

For instance, where any of the IIAR Suite of Standards for ammonia has been adopted by a model code, the model code with have a general statement something such as “…for anhydrous ammonia refrigeration systems, refer to IIAR…”.

MODEL CODE ADOPTIONS OF IIAR STANDARDS

2024 IFC

IIAR 2, 6, 7, 8, 9, CO2

2024 IMC

IIAR 2, 3, 4, 5, 6, and CO2

2024 NFPA 1 FIRE CODE

IIAR 2, 6, 7, 8

2023 NFPA 70 NEC

IIAR 2

2024 UMC
IIAR 2, 3, 4, 5 6, and CO2

You can see that each Model Code has proposed adoptions for at least one or more of the IIAR Suite of Standards for ammonia refrigeration and the IFC, IMC, and UMC has proposed adoptions for the IIAR CO2 standard.

CODE ADOPTION ADMINISTRATION:

Figure 1 (on page 31), Figure 2 (page 32 and Figure 3 (page 33) are examples of proposal submittals for IIAR CO2 code adoptions.

Any questions pertaining to the Codes & Standards Road Map Overview, SNAP (Significant New Alternatives Policy Approvals) for Ammonia, CO2, or HC refrigerants as natural refrigerants, the
Purpose and Scopes of the Ammonia Suite of Standards, the CO2 Standard, and/or the IIAR HC Standard in Development as what they apply to and what they do not apply to, and the Model Code Adoptions of IIAR Standards, please contact Tony Lundell, IIAR Senior Director of Standards & Safety at tony_lundell@iiar.org