Greenhouse Gases and the Environment

Substances used in older refrigeration media, such as CFC (R-12) and HCFC (R-22), are harmful to the ozone layer and thus regulated in MARPOL 73/78, the Regulations for the Prevention of Air Pollution from Ships (Annex VI, regulation 12). Both CFC and HCFC are prohibited in new installations, and even though the substances are becoming uncommon, they still exist. Ships using these ozone-depleting substances (ODS in short) are required to maintain an ODS Record Book with running entries documenting any supply, recharging, repair, discharge, or disposal operations. Newer HFC refrigerants are not ozone-depleting, but as they have very high Global Warming Potentials (GWP measured in KgCO2 equivalence), they are illegal to vent into the atmosphere according to MARPOL Annex VI.

In all major classification societies, recovery systems and cylinders are mandatory. In Europe, GWP thresholds for HFCs have been significantly lowered, and some HFCs will, due to their high GWP, be banned in the future.

For more details, see Regulation (EU) No 517/20144 on fluorinated greenhouse gases.

Leak Checking 

In Europe, and onboard European ships, regulations govern the handling of greenhouse gases and determine how frequently leak searches should be conducted. How often you need to perform the leak searches depends on the size of the unit in question, measured in kilograms of CO2 equivalents. Where leakage detection systems are installed, the time between leak searches can be doubled. If a leakage detection system is in place, the system has to be checked at an interval of 12 months.

Leak Check Intervals 

For equipment that contains fluorinated greenhouse gases, in quantities of tonnes of CO2 equivalent, the leak check intervals are as followed:

Or, for equipment that contains fluorinated greenhouse gases, but where a leakage detection system is installed:

What Kind of Work Can I Do?

You can perform leak checks, but note that in Europe and the US, you need to hold a Certificate of Competence to perform work that involves opening the system. International shipping, apart from EU- and US-flagged vessels are not affected by these rules. A consumption logbook is mandatory with most major classification societies, but you can also put this data in maintenance system software.

Necessary Equipment

You should keep the tools required for reefer equipment service or repairs on board, along with a recovery bottle for the refrigerant. You need the following things:

To ensure a properly working refrigeration unit after maintenance, you will need a vacuum pump to eliminate any moisture in the system.