Location and design specifics

Location of the system with A2L refrigerant

Many countries limit the use of flammable refrigerants. The national and local laws and rules always apply. Here the rules often depend on, how well instructed the people are, that work with or around the system.

Where the rules allow the use of flammable refrigerants, or no specific national or local rules and regulations exist, the rules of EN378-1 or ISO5149-1 can give guidance for the maximum charge that can be handled safely, depending on room size, ventilation and access or occupancy by people, for example:

• Where instructed personnel is working, a refrigerant charge might be applied, that can not form more than 20 % of lower flammability limit (LFL) in any of the rooms, where parts of the refrigeration system are located.
• Where the 20% are exceeded, a gas warning system, that shuts off all standard electrics in the room can be used.
• A ventilation of the machine room, or the place, where the major part of the refrigeration system is placed, improves the situation. This is often done by the condenser fan already.

System design specifics for A2L refrigerants

The components and materials of the refrigeration system have to be compatible to the refrigerant chosen, which is also valid for A2L refrigerants. As some of these refrigerants have different compatibility behavior, information on compatibility from the component manufacturer is very important.

In many countries special rules or regulations apply for flammable refrigerants. In the EU, the demands of the Pressure Equipment Directive 2014/68/EU (PED) to the manufacturing and quality control increases. This means, that pressure equipment, like liquid receivers, pipe lines, valves, condensers and so on have to be checked for their categorization. Small and medium pressure vessels or some pipe lines can move from one category to the next higher, due to different limits for non dangerous and dangerous refrigerants, for the categories I to IV. If the pressure equipment is not released for flammable refrigerants, it can mostly not be used. Check the type label of the vessels and the documentation of the other components. The risk assessment for the system has to contain the risks due to the flammability. This assessment has to include all life phases of the system, including transport, installation, commissioning, operation, maintenance, repair and decommissioning.

For estimation of risk while working with A2L refrigerant → examples for maintenance, repair and retrofit.