The Montreal Protocol aims to protect the ozone layer. In the protocol, the "Kigali Amendment" was adopted in October 2016 to reduce HFC refrigerants in phases to curb global warming. In Japan, the Fluorocarbon Emissions Control Act came into effect and the regulation on centrifugal chiller products using HFC refrigerants with a high global warming potential (GWP) will be started in fiscal 2025 (starting April 1, 2025). Mitsubishi Heavy Industries Thermal Systems, Ltd. newly developed a centrifugal chiller "JHT-Y" using the HFO-1234yf refrigerant with a GWP of less than 1, which achieved the performance, compact size and cooling capacity range equal or superior to those of an existing centrifugal chiller using HFC-134a. This report describes the technologies adopted for the development of the JHT-Y and the comparison with the existing product.
