Hillphoenix’s acquisition of the Danish transcritical CO2 system manufacturer Advansor in 2011 started it on the road to becoming a leading manufacturer in its own right of transcritical systems in North America, with numerous installations in supermarkets and some industrial plants.

While Hillphoenix’s initial transcritical racks were made in Denmark, Hillphoenix, based in Conyers, Ga., and Advansor now run their transcritical operations independently in two marketplaces divided by an ocean. But the two companies maintain a working relationship to stay on the same page and share technology insights, said Kim Christensen, managing director, Advansor, in an interview with R744.com at the Chillventa 2016 trade show in Nuremberg, Germany, last month.

“What we try to do is have technology meetings every week so information on any new components and new designs is exchanged,” he said. “We should be aligned on the use of different components and try to consolidate to one or two suppliers.”

Advansor, with a decade of experience marketing transcritical CO2 systems and 2,500 racks in operation across at least 1,800 European supermarkets, is positioned to help Hillphoenix with any issues related to the technology, Christensen noted.

By operating in Europe, Advansor has certain advantages. It is able to incorporate component technology that is readily available and has become more affordable in a mature marketplace. Hillphoenix, by contrast, is not always able to secure these European-based components if they have not been UL certified, noted Scott Martin, Hillphoenix’s director of sustainable technologies.

In Europe, about 2,500 transcritical racks are produced annually, including about 600 by Advansor. The much larger production scale in Europe means that for a transcritical system in a 16,150-square-foot (1,500-square-meter) store “we are at price parity” with a comparable HFC refrigeration system, said Christensen.

There is still a price gap between the two technologies in the U.S., he said. “The U.S. is where we were six or seven years ago.”

“The U.S. is where we were six or seven years ago.”

Kim Christensen, Advansor

In North America, Hillphoenix markets its standard Advansor-brand transcritical rack system in an 8 x 4 configuration (8 MT compressors and 4 LT compressors, along with a smaller version called AdvansorFlex in an 3 x 2 compressor configuration; AdvansorFlex uses less expensive components to bring the price closer to that of HFC technology.

Advansor, too, has a standard compSUPER system (80 kW to 300 kW) and a downsized version for smaller stores called the Valuepack (up to 80-90 kW), which is its highest volume rack with 300 units per year; both employ technology comparable to the U.S. versions.

But Advansor offers other models as well. These include a larger industrial version called the compINDUSTRI, and a SIGMA Valuepack system that includes a cassette offering heating and air conditioning functions.

Advansor has also developed a small COcondensing unit (10 kW or less) for retailers and pharmaceutical companies. This remains the only product that it still ships to the U.S. “Transportation costs on this are not high, so we can manage,” said Christensen.

And the company plans to debut at Euroshop next March another model, between 25 kW and 30 kW, that falls between the condensing unit and the Valuepack. The new system is designed for “small discounters and convenience stores that we are now targeting,” he said, adding, “In Europe, all of the retailers are interested in small stores and we have to be where the money is.”

Christensen believes that with technical enhancements, “there is no limit on ambient temperature” for a transcritical rack. For example, hundreds of Advansor’s transcritical racks have a parallel compressor (compared to one Hillphoenix installation in the U.S.). Subcoolers are also often used, and in climates with many high-temperature hours, he recommends using an adiabatic condenser.

Advansor also offers a gas ejector, which adds four to five percentage points to the 10%-11% energy savings gained with a parallel compressor, Christensen said; the company is also developing a liquid ejector, which he does not consider a mature technology. He also believes controllers for gas ejectors are not sufficiently developed.

“What is important for Hillphoenix now is to get more parallel compressor systems operational like we did four years ago and put that into the market,” he said. “That would be by far their biggest gain. Then on top of that they can follow our lead with ejectors.