ISO 817:2014/Amd 1:2017

Overview

ISO 817:2014/Amd 1:2017 is an important amendment to the international standard for refrigerants titled "Refrigerants - Designation and safety classification." Published by the International Organization for Standardization (ISO), this document updates the third edition of ISO 817 issued in June 2014. The amendment, released in November 2017, introduces clarifications and revisions related to the designation, classification, and safety criteria of refrigerants used globally in refrigeration and air conditioning systems.

This standard addresses the classification of refrigerants based on their safety characteristics, providing a framework to assess flammability, toxicity, and other critical parameters. The update enhances clarity and precision for stakeholders in the HVAC-R industry, ensuring compliance with evolving safety and environmental requirements.

Key Topics

The amendment brings several key modifications that refine the approach to refrigerant classification and designation:

• Auto-Ignition Temperature Definition: Addition of a clear definition for auto-ignition temperature (AIT), describing it as the lowest temperature at which a substance ignites spontaneously under normal atmospheric conditions without an external ignition source like a flame or spark.

• Blend Composition Tolerances: Specification of mass fraction tolerances for refrigerant blends to the nearest 0.1%, with a maximum allowable deviation of 2% above or below the nominal composition. Components comprising less than 0.6% by mass are excluded from blend designation and classification considerations.

• Classification Tables Update: Replacement of the classification tables (5, 6, and 7) with a directive to consult the most current versions available online. These tables classify refrigerants based on safety criteria such as toxicity and flammability.

• Conversion Methodology: Introduction of a formula for converting volumetric ratios (ppm by volume) into volumic mass (g/m³), ensuring consistent application of molecular mass values according to blend composition.

• Data Tables Relocation: Movement of key safety classification and Refrigerant Concentration Limit (RCL) data tables (formerly in Annex E) to an online repository to maintain currency and accessibility.

Applications

This amendment to ISO 817 plays a critical role for:

• HVAC-R Manufacturers: Ensuring that refrigerant designation and safety classification are accurately observed during system design and component manufacturing, adhering to international safety standards.

• Safety Assessors: Applying consistent and up-to-date safety data for refrigerants when performing risk assessments related to flammability and toxicity in refrigeration and air conditioning installations.

• Regulatory Bodies: Establishing compliance frameworks based on standardized refrigerant safety classifications, enabling effective regulation and monitoring in line with environmental and safety mandates.

• Researchers and Developers: Accessing precise definitions and blend tolerances to innovate and develop new refrigerants or refrigeration technologies that meet stringent safety and performance criteria.

Related Standards

For comprehensive understanding and application of refrigerant safety and environmental management, ISO 817:2014/Amd 1:2017 is often used in conjunction with related international standards such as:

• ISO 5149 - Refrigerating systems and heat pumps - Safety and environmental requirements: Covers safety requirements for refrigeration system design, incorporating refrigerant classification standards.

• ISO 46xx series - Refrigerant testing and identification: Details test methods for refrigerant properties that complement classification data found in ISO 817.

• IEC 60335-2-40 - Safety of electrical appliances for household and similar purposes: Includes requirements related to refrigerants used in heat pumps and air conditioners from an electrical appliance safety perspective.

• ASHRAE Standard 34 - Designation and Safety Classification of Refrigerants: Provides safety classification similar to ISO 817 and is widely referenced in North America, highlighting the relevance of consistent refrigerant classification practices globally.

Conclusion

ISO 817:2014/Amd 1:2017 is a vital amendment that reinforces the safety classification and designation system for refrigerants worldwide. It enhances the accuracy of definitions, classification, and compositional tolerances, supporting safer design, operation, and regulation within the refrigeration and air conditioning sectors. Professionals involved in refrigerant handling, manufacturing, and regulation should reference the latest tables and online resources stipulated by this amendment to ensure compliance and promote best safety practices.