CEN opens public enquiry on proposed revision of EN 378

The European Standards Organisation CEN is set to launch a public enquiry on the proposed revision of EN 378, the standard for refrigeration, air-conditioning, and heat pump systems. AREA urges its members to participate in the process, which may significantly affect system design and installation for both factory-built and site-installed equipment.

EN 378:2016 is currently structured in four parts. The revision includes several major changes: a significantly revised method for determining charge limits for flammable refrigerants, and the conversion of Annex E in Part 1 into a standalone Part 5 to ease future updates as new refrigerants emerge. Additionally, EN 378 Part 4 will be replaced with EN ISO 5149-4, with no change in technical content.

The enquiry will run from 3 July to 25 September 2025. National standards bodies in CEN member countries will facilitate access to the draft and collection of comments. Each country will submit one national vote and a compilation of comments to CEN. Comments received by the deadline will be reviewed by the TC182 Working Group between October 2025 and January 2026, in preparation for a final draft.

The formal vote on the final draft (FprEN) is expected in May 2026. Approval requires a majority of member votes and a population-weighted threshold. If successful, the updated standard will be published as EN 378:2026, replacing the 2016 edition.

Participation is open to the public in all CEN member states via national standards bodies. Only members of national mirror committees can directly influence the vote. AREA provides links to national portals and additional resources to support stakeholder engagement.

AREA notes that EN 378 is partly harmonised with the Pressure Equipment and Machinery Directives for CE marking. However, it does not address ATEX directive requirements and will remain outside that scope under the proposed revision.

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