Keep cool

The climate is changing. In order to become more climate-friendly, companies around the world are producing new refrigerants – all that is missing are the right refrigeration oils. At the forefront of development is the FUCHS Group.

Refrigerants and refrigeration oils – they come into intensive contact in the refrigerant circuit. Mixed together they are essential to the functioning of, for example, a refrigerator. In much simpler terms, this working relationship functions as follows: the refrigerant cools, while the oil lubricates and protects against wear. One problem persists from the very beginning: if the refrigerant escapes, it can have a negative impact on the climate. For decades, the search for climate-friendly refrigerants has therefore led to the development of many new products. And each of these needs its own compatible oil.

As a manufacturer of refrigeration oils, FUCHS has for decades found itself confronted by a steady stream of new developments and new legal specifications in terms of climate protection. “That began in the mid-80s,” remembers Wolfgang Bock, Head of Product Management for Industrial Oil at FUCHS SCHMIERSTOFFE GMBH in Mannheim. “Back then, the sector was facing a turning point. After CFCs were banned due to their ozone-depleting effects, alternatives had to be developed. Fluorinated refrigerants – known as HFCs – were created. They required new, customized, ester-based refrigeration oils. These new refrigerants were adopted worldwide very quickly. At that time, we became one of the world market leaders in the area of climate-friendly refrigeration oils, with an extensive product portfolio of fully synthetic polyester-based refrigeration oils.”

„The number of refrigerants on the market is constantly rising. Companies such as FUCHS have to be quick and innovative in the development of new, compatible oils.“

Dr. Karin Jahn, CEO of the Research Council for Refrigeration Technology

However, another transition is already taking place. The HFC refrigerants that were introduced are being replaced by natural refrigerants such as carbon dioxide (CO₂), hydrocarbon refrigerants (e. g. propane, propene) and ammonia (NH₃). In addition, fluorinated olefins (HFO) will be used in many applications in the future. Why?

The HFCs did not do any more damage to the ozone layer, but they did have a negative impact on global warming. Their global warming potential (GWP) is high, at between 1,000 and 4,000. Fluorinated olefins have a significantly lower GWP. The existing refrigeration oils have to be tested for compatibility and miscibility with these new substances and their compounds, and if necessary, adjusted. This creates new market opportunities for lubricant manufacturers such as FUCHS.

Natural refrigerants such as CO₂ and ammonia also need an optimal refrigeration oil. “Some special products from our RENISO C range work very well in conjunction with the refrigerant CO₂,” says Wolfgang Bock and adds: “Generally speaking, you have to keep cool and maintain a clear focus to make sure that you do not lose sight of the big picture.”

The right refrigeration oil for the respective refrigerant is so important because both have a direct impact on the compressor mechanism, the “driving force” in the refrigerant circuit. A suitable refrigeration oil forms a homogeneous mixture with the respective refrigerant and provides the compressor’s moving parts with reliable protection against wear. It has to demonstrate a defined viscosity and should not be too viscous because without the corresponding fluidity, it will be unable to move properly at low temperatures through the refrigerant circuit and disturb operation of the refrigerating unit.

The Research Council for Refrigeration Technology was founded in 1957 for fundamental developments in the area of refrigeration and was accepted into the German Federation of Industrial Research Associations in 1959. Members of the research council include plant manufacturers and operators, research institutions, industry associations, manufacturers of refrigerant compressors, components and refrigerants, as well as lubricant manufacturers such as FUCHS. The Research Council for Refrigeration Technology promotes technical and scientific research on refrigeration and heat pump technologies and their impact in practical applications. “For a company such as FUCHS, active participation in the Research Council for Refrigeration Technology is a matter of course,” says Wolfgang Bock, who is also Chairman of the Research Council for Refrigeration Technology Executive Board. “For us, it was always a matter of innovative developments. And where, if not in a research association with all those involved sitting at the same table, can future technologies be implemented quickly and efficiently?,” adds Christian Puhl, Product Manager and Application Engineer for Refrigeration Oils at FUCHS.

“The research required for refrigeration and heat pump technologies has, in particular, developed in such a way that new technologies and therefore new components and operating materials are in demand due to the current legislation. There is also a specific need for research and development in the areas of commercial, industrial and transport refrigeration, and in heat pump and low-temperature technologies,” explains Dr. Karin Jahn, CEO of the Research Council for Refrigeration Technology. “The research council members are working on these issues together within the framework of joint industrial research. Each member company has the opportunity here to introduce proposals for a specific project. The research advisory board, in which FUCHS is represented by Christian Puhl as an expert, is responsible for implementation.” The issue of refrigeration oils is an important aspect of almost all projects, not least thanks to FUCHS’ intensive involvement. This is because a refrigerant circuit does not work without a suitable oil. Refrigerant and lubricant have to be perfectly coordinated to ensure chemical compatibility. This also enables refrigeration oils to make an important contribution to climate protection and energy efficiency.

The requirements of refrigeration oils are therefore clearly defined, which is precisely why FUCHS is working intensively in the Research Council for Refrigeration Technology. Mutual exchanges between experts are what will drive innovation extremely fast. This is important because new developments and legal requirements that are appearing all the time call for ever-faster reactions. “The sector has for some time found itself confronted by a number of new refrigerants,” says Dr. Karin Jahn. “Companies such as FUCHS constantly have to readjust to this and develop new, compatible oils. There is no definitive clarification on which refrigerant will ultimately be used for each application.” Whether in refrigerated counters in supermarkets, in air conditioning systems or in the refrigerator, each application brings with it new requirements and can be operated using various refrigerants. The oil in turn has to be specifically adapted to requirements and refrigerants. No simple undertaking, “but we are working on it,” says Wolfgang Bock. “FUCHS is tackling these challenges and is working flat out to find new solutions.” FUCHS refrigeration oils are therefore always the first choice.