The new natural refrigerant blend R-723 presents the same advantages as ammonia (i.e. high specific evaporation heat and insignifigant GWP) and offers further benefits: it can be used in copper systems and offers full mineral oil solubility. R-723 is made up of 60 % ammonia and 40 % dimethyl ether, a hydrocarbon, and is classed a B2 refrigerant. This composition gives rise to an azeotropic boiling mixture. According to researchers from ILK and DTI, the volumetric cooling performance is slightly higher than that of ammonia, and the flatter vapour pressure curve is even able to improve energy efficiency. The compression temperature at the pressure valve is around 20 K lower in comparison with ammonia.