What makes a good refrigerant?
suitability for target use and equipment type; capacity and efficiency → boiling point; critical temperature; heat of vaporisation; & stability at operating temperatures; materials compatibility.
requirements for the specific application → flammability; toxicity; risk mitigation measures.
Climate change impact (refrigerant and energy related emissions); other environmental effects -VOC (POCP- photochemical ozone creation potential), atmospheric breakdown products; Zero or near-zero ODP; recyclability
Refrigerant selection is made taking all the criteria of a refrigerant into account for a given application, as well as lifetime emissions from energy use and any refrigerant emissions.