German components manufacturer RSG began series production of valves for CO2 (R744) refrigeration systems in 2023. However, its experience manufacturing valves stretches back to 1985, when the company began designing valves for use in mechanical and plant engineering, the food industry and the medical space, in addition to the HVAC&R sector.
Mathias Kreß, Product Manager at RSG, told NaturalRefrigerants.com that the company is “still in the early stages” of working with natural refrigerants, but it is striving to carve out a niche for itself in the sector with its focus on the compactness of its valves, their modularity and its own resource efficiency during the production process.
“We see it as our responsibility to develop resource-saving valve solutions that are both technically and ecologically sound,” said Mr. Kreß. “That is why we attach great importance to the efficient use of materials, energy-efficient operation and a long service life.”
NaturalRefrigerants.com recently spoke with Mr.Kreß about RSG’s work designing and manufacturing valves for CO2 refrigeration systems along with why it decided to join the NaturalRefrigerants.com marketplace.
This interview has been edited for length and clarity.
RSG has reported on its focus on manufacturing small valves for CO2 systems. Why are small valves so important?
Mathias Kreß: Small and compact valves in particular play a central role in CO2 systems. They enable space-saving system designs, reduce material requirements and contribute directly to the energy efficiency of the overall system through optimized flow geometries. At the same time, the operating pressures place particularly high demands on design, materials and manufacturing processes.
The development of our compact CO2 valves follows a clearly structured process, with the design, material selection and manufacturing technologies all consistently geared toward efficiency and durability. In our view, this approach is 100% in line with the switch to natural refrigerants. Here, too, environmental considerations are clearly at the forefront, from reducing climate-damaging emissions to the sustainable use of resources.
It is precisely this combination of compact design, high energy efficiency and above-average service life that our customers particularly appreciate. Despite the high pressures in the CO2 range, our valves achieve an exceptionally long service life and thus make an important contribution to reliable and sustainable refrigeration and air-conditioning systems.
RSG also develops customized valves. Can you share an example of why a customer would need a custom valve?
MK: Customer-specific requirements arise primarily when systems deviate from the classic CO2 operating parameters. For example, we have developed valve variants that are designed for lower pressure ranges and can be used reliably at extremely low temperatures down to −80°C (−112°F). Such adaptations are particularly necessary for special applications or specific system architectures.
Another important aspect of customer-specific developments is the modular design of our valves. Our CO2 valves consist of two main components: a valve housing and a screw-in cartridge, offered as a set. This concept allows the customer to first solder the valve housing into the system without subjecting the actual valve or the sensitive cartridge to thermal stress. The cartridge is only screwed in after the soldering process, which significantly simplifies installation and reduces the risk of damage.
This modular approach also offers clear advantages during operation. For preventive maintenance work or during servicing, the pilot control unit can be replaced without great effort and without in-depth specialist knowledge. This reduces downtime and lowers operating costs.
In addition, the use of multiple CO2 valves in refrigeration systems often requires complex piping. Together with our customers, we are developing customer-specific system blocks that integrate multiple valves, sensors and pressure switches into a compact unit. These system solutions significantly reduce the installation and planning effort on the customer’s side. The simple integration into such system blocks is further facilitated by the modular, two-part design of our valves.
“Despite the high pressures in the CO2 range, our valves achieve an exceptionally long service life.”
Mathias Kreß,
Product Manager at RSG
What natural refrigerant trends is RSG watching in the HVAC&R industry?
MK: In the wake of the [EU] F-gas Regulation, all manufacturers will sooner or later be forced to address the issue of natural refrigerants. Leading refrigeration system suppliers have been working on this for some times, as have leading component manufacturers. We are still in the early stages of designing and marketing refrigeration systems with natural refrigerants.
Component suppliers are forced to keep up and provide the appropriate solutions at an adequate pace. The industry is thus feeling its way toward the specific challenges. Only those who are innovative and well positioned around R&D will be able to keep up. Overall, the focus is increasingly on the economic efficiency and durability of the systems.
Why did RSG decide to join the NaturalRefrigerants.com marketplace?
MK: As a medium-sized company, we believe it makes sense to promote our valve solutions for natural refrigerants internationally and to engage in direct dialogue with equipment manufacturers. This allows us to better understand market requirements and tailor our research and development accordingly.
We are building on the network and believe that, in collaboration with equipment manufacturers, we can make a valuable contribution to the global climate.
