CEN Opens Public Enquiry on Revised EN 378 Safety Standard for Refrigeration Systems

CEN has released the enquiry version of the revised EN 378 safety standard (prEN 378:2025) for vote and comments by national standardisation committees and other stakeholders. The current edition, EN 378:2016, prescribes requirements for the design, testing, installation and operation of refrigeration, air conditioning and heat pump systems of all sizes.

Structure of the revised standard

The draft comprises four parts:

• prEN 378-1 – general, definitions, charge limits
• prEN 378-2 – system design, construction and testing
• prEN 378-3 – installations
• prEN 378-5 – refrigerant data

Part 4, covering operation, maintenance, repair and recovery, is being replaced by ISO 5149-4.

Why the revision matters for natural refrigerants

Safe application of natural refrigerants is a prerequisite for their wider use. Each carries distinct challenges: R717 (ammonia) has higher toxicity and lower flammability; R744 (CO₂) operates at higher pressures than conventional fluorinated refrigerants; and hydrocarbons such as R290, R1270 and R600a have higher flammability. The standard must therefore ensure system safety while remaining flexible enough to allow cost-effective designs with natural refrigerants and to enable innovation in applications hitherto dominated by other refrigerants.

Eurammon's assessment

With substantial changes introduced in the draft, especially in Part 1, eurammon welcomes the standard's more flexible and risk-based design approach, which could better accommodate the unique properties of R717, R744 and hydrocarbons. However, the organisation notes that some constraints still remain and urges further improvements, particularly to charge limit restrictions and overly prescriptive safety caps that it says still pose barriers to wider application of natural refrigerants.

Call to stakeholders

Eurammon urges all members and supporters of natural refrigerants in CEN member countries to support the revised standard by voicing expressions of approval to their national standardisation committees.

For more information, see the eurammon webinar presentation on the EN 378 revision.

Source: eurammon.