EN378 refrigerant charge compliance checker

UK – Certification body F-Gas Register has published a technical bulletin (TB13) looking at compliance with BS EN378:2016, the safety standard for mechanical refrigeration and air conditioning systems, including heat pumps.

1 WHAT IS BS EN 378:2016?

BS EN378:2016 Refrigerating systems and heat pumps – safety and environmental requirements is the accepted safety standard for mechanical refrigeration and air conditioning systems, including heat pumps. The standard is constantly being reviewed and updated so it is important to ensure that you are always referring to the most up to date version – unless you are looking at historic systems.

Knowledge of the standard is essential for all those responsible for working with refrigerating systems, particularly designers as it highlights important information such as refrigerant charge limits, pressure testing limits, piping requirements, etc.

Whilst standards do not have any specific legal standing in themselves, and it is not a legal requirement to follow a standard, work carried out in conformance with the standard would provide strong supporting evidence in the case of a legal dispute.

This standard comes in four parts – each covering specific requirements.

2 WHAT DOES EACH PART COVER?

Part 1 is Basic Requirements, Definitions, Classification and Selection

As well as covering the definitions used throughout the other parts of the standard, this part covers physical properties of refrigerants common at the time of publication; specifies allowable charge limits in accordance with occupation category, etc; calculation tables for charge sizes in Annex C; and examples of how to use additional measures to allow charge sizes above those calculated from the tables.

• It is aimed at the plant designer, the installer, and the building owner/manager.

Part 2 is Design, Construction, Testing, Marking and Documentation

This part covers in some detail the requirements for pressure tightness and strength testing and is mandated under the Pressure Equipment Directive. Important aspects such as safety control systems and pressure relief valves are also covered in this section.

• It is aimed at equipment manufacturers, the plant designer, and the installation or service & maintenance teams.

Part 3 is Installation Site and Personal Protection

This part covers site safety issues but not those directly involving refrigerants – the requirements for refrigeration safety such as systems in occupied spaces is covered in Part 1. It does, however, cover issues such as ventilation requirements, alarms and refrigerant leak detectors in machinery rooms.

It is aimed at the building owner/manager, and the designer and site manager where applicable.

Part 4 is Operation, Maintenance, Repair and Recovery

This part covers existing system installations as well as new ones and so can be applied retrospectively. Safety recommendations during maintenance visits include subjects such as oil changes and handling of contaminated recovered refrigerants.

• It is aimed at service and maintenance personnel and building owners/managers.

3 CHARGE COMPLIANCE

The charge limit calculations can be tricky under some circumstances with complicated equations to apply.

In 2017 an app was created by Graeme Fox, now of the F-Gas Register, which was distributed free of charge via AREA at
https://area-eur.be/publications/area-app-calculator-fgas-and-en378 for iOS and Android devices.

The app was designed to give engineers in the field a quick CO₂ tonnes equivalent calculation for various refrigerants but was also a quick compliance checker tool for EN378:2016.

There have been some issues with the iOS store including downloading problems – this is being looked into by AREA.

In the meantime, if members do not have access to the app or would prefer a desktop version, please email
[email protected], for the attention of Graeme Fox, advising what your F-Gas registration number is and a copy of the EN378 calculator spreadsheet will be sent free of charge.

• Note: this document is based on knowledge available at the time of publication and is meant for general purposes, not for reliance on in relation to specific technical or legal issues, in which case you should always seek independent advice. No responsibility of any kind for any injury, death, loss, damage or delay however caused, resulting from the use of the advice and recommendations contained herein, is accepted by the authors or others involved in its publication (including the F-Gas Register). 18/06/2025