R-513a is a zeotropic blend containing refrigerants from the hydrofluoro-olefine (HFO) family. It is designed to replace R134a in domestic, commercial and industrial refrigeration applications as well as in air conditioning, liquid cooling and PAC. It is a blend of R-1234yf and R-134a in the following proportions: 56% C3H2F4 · 44% C2H2F2