As an example of the feasibility of adopting transcritical CO2 even in hot Asian climates, Meier told his audience that Teko is now running a transcritical R744 system in a Middle Eastern country, Israel, with the end user there having just ordered a second rack for a cold storage installation.
However, the adoption of natural refrigerants in Asia isn’t progressing as fast as it could, according to Meier. The lack of movement on the Asian markets, compared to, for example, Latin America, is something that makes him feel a “bit sad,” he said, while praising the skills of Asian refrigeration engineers and stressing that the lack of movement isn’t due to legislation differences.
One of the aspects driving the uptake of natural refrigerants in Latin America, according to Meier, is the “green marketing” of high-end supermarkets, where wealthy customers that are keen to protect the environment do their shopping. Once contractors gain the necessary experience, they are no longer afraid to promote it elsewhere.
“After the contractors have installed the first [R744] unit, and they see everything is running smoothly, they see there is not a big difference concerning Freon, and surprise – It was not a big difference anymore.”
Meier explained that the introduction of R744 technology to a new market is a matter of trust. “The operator has to trust the contractor and the contractor has to trust the manufacturer; otherwise you cannot do any business if there is no trust in technology, in relationships, and in the total market.”
Another common worry for engineers not used to working with CO2 is the high pressure. However, “the high pressure is not a problem to handle,” Meier stressed; “the components are designed for it.”
There are still several considerations a new end user should make before moving from f-gas refrigerants to R744, Meier said, such as pipes, stocking of spare parts and availability of refrigerant and oil.
Meier listed a number of things to consider.
- Dimensioning of components: Due to the higher volumetric refrigeration capacity of CO2, the piping dimensions are smaller, especially for the suction lines. Meier recommended Danfoss’ free Cool Selector software for calculations.
- Cleanliness: CO2 is a good refrigerant, but it has small molecules, meaning that a lot of dirt from the pipes can get into the system, and then valves can get blocked. So keeping the system and components clean is important, even more so than with traditional refrigerants.
- Pressure: High pressure leads to a number of testing procedures, both for manufacturers and operators, but this is not a difficult issue for technicians to handle, Meier said.
- Correct filling: As with f-gas systems, over and under filling can cause contamination, and is not good for the system, Meier said.
- Maintenance: After installation, users should always have spare controllers, sensors and maintenance materials on site, as a break down can cause long delays and be costly if spare parts can’t be sourced locally in new markets. Cleaning and exchanging oil filters are also very important, because this is where all the dirt ends up, and it is an aspect that is often underestimated, according to Meier.
Meier also stressed that Teko’s recommendation would be to always install safety valves outside the building.
After the contractors have installed the first [R744] unit, and they see everything is running smoothly, they see there is not a big difference concerning Freon,”Andreas Meier, Teko