2020 Volume 65 Issue 8 Pages 505-510
As with automotive lubricants, the trend in refrigeration oils for refrigerators is toward lower viscosities, in pursuit of higher energy efficiency. A viscosity grade (VG) of 32 was once common for refrigeration oils. Recently, however, an extremely low viscosity refrigeration oil (VG3) for refrigerators is needed. Extremely low viscosity oils such as VG3 cause problems in flash points and anti-wear properties, resulting high friction coefficient in low speed region. However, it was found that the problem could be overcome by improving the base oil blending and additive formulation, and VG3 oil can contribute to the high efficiency on refrigerators. It is expected that improvements of refrigeration oil for higher efficiency will continue in the future.