Refrigeration retrofit

A refrigeration retrofit replaces a ship’s ozone-depleting or high-GWP refrigerant and the matching components to meet MARPOL Annex VI Regulation 12 and the Montreal Protocol with its Kigali Amendment. R22 (HCFC), banned from new installations and phased out for servicing, is replaced with R134a, R404A, ammonia (R717), or CO2 (R744) for provision plants, reefer containers, and air conditioning. The swap is not drop-in: it changes compressor displacement, oil type (POE for HFCs), expansion devices, and pressure ratings, and CO2 systems run transcritical at much higher pressure. Class approval and an updated refrigerant log and leak-detection arrangement follow the conversion.