A major cause of reduced efficiency in refrigeration equipment arises from using conventional refrigeration oils as opposed to the specialised synthetic lubricants required for heating, ventilation, and air-conditioning (HVAC) applications. “Failure to use the correct refrigeration oils can result in leaks, reduced filter lifespan, and increased energy consumption,” says Gerald Langley, at Fuchs Lubricants South Africa.
Apart from being able to run in a temperature range from minus 45°C up to 80°C to 100°C, these specialised oils must also be compatible with the different types of gases used in refrigeration units. Such units range from ordinary compressors to automotive air-con compressors, with Fuchs supplying major OEMs such as Scania and MAN.
“Our main focus, however, is on major industrial applications,” says Gerald. It runs the gamut from refrigerated trucks to standard and industrial fridges and includes carbon dioxide (CO2) compressors. While standard mineral oils have traditionally been used, the latest trend highlights the increasingly important role of synthetic oils due to their increased lifespan and reduced service intervals, which assists in reducing costs and boosting return on investment.”
Horses for courses
Products on display at the recent Frigair show included Fuchs Reniso 32, 46 and 68 high-quality Naphthenic mineral lubricating oils designed for the lubrication of refrigeration and air-conditioning compressors, featuring good chemical stability when working with commonly used refrigerants. In addition, Reniso Triton SEZ 68 is a fully synthetic, ester-based refrigeration oil for fluorinated HFC and HFO refrigerants such as R134a, R404A, R507, R407C, R410A, R1234yf, and R1234ze.
Depending on the viscosity, the refrigeration oils are recommended for hermetical, semi-hermetical, and open piston compressors and for screw-type and turbo-compressors. Reniso Triton SEZ 22, on the other hand, is especially suited for deep-freeze systems operating with R23. Reniso C 85 is a synthetic refrigeration oil based on special polyolesters with anti-wear additives for use with CO2 as the refrigerant in subcritical and transcritical applications.
