Danish refrigeration systems and components manufacturer Danfoss showcased its updated transcritical CO₂ (R744) condensing unit for use in either medium- or low-temperature (MT/LT) applications at the 2025 AHR Expo.

When the company released the unit last year, which has a cooling capacity of 86,000BTU (25.3kW/7.2TR), it only accommodated MT applications. Dean Groff, Field Services Manager at Danfoss, told NaturalRefrigerants.com that the updated unit will be released mid-year in North America. The 2025 AHR Expo was held in Orlando, Florida, from February 10–12.

“The modular roof-mounted unit works well for new convenience stores, and it allows capacity shifting in supermarket retrofits,” Groff said, adding that the company is seeing a lot of interest in California. By the end of the year, Danfoss expects to install the updated unit in up to 50 stores, depending on production capacity and the capabilities of local contractors to work with CO₂. The unit supports remote cases, with the number of cases dependent “on the load of each case up to the capacity of the condensing unit at the desired rating point,” according to Groff.

Groff noted that the unit could also support stores with refrigeration capacity issues in the hot summer months ‒ even non-CO₂ systems ‒ with the addition of an available heat exchanger.

“Adding the CO₂ unit to a struggling system negates the need for sprinkling water on an existing unit to increase capacity,” Groff said, making it especially applicable in places like Nevada, which restricts evaporative cooling due to high water use.

The next innovation on the horizon for the unit is delivering MT and LT loads simultaneously. “We are close to figuring out how to do that with the unit in transcritical operation,” Groff said, indicating that the technology should be released next year.

In addition to the CO₂ condensing unit, Danfoss showcased its award-winning Bock CO₂ compressor and new universal controller at the event.

Industrial compressor: The 6-cylinder BOCK HGX56 CO₂ compressor was named the winner in the refrigeration category of the 2025 AHR Expo Innovation Awards.

• The variable speed semi-hermetic compressor ‒ for industrial applications, cold storage, heat pumps and ice rinks ‒ offers up to 135kW (38.4TR) of cooling capacity and 360kW (102.4TR) of heating.
• “The design keeps oil in the compressor, which increases efficiency,” said Groff, with gears directing the refrigerant flow.
• It has a 1.95 EER for cooling and a 4.49 COP for heating, according to its product brochure.

Entire store control: The company redesigned its original chiller controller to create its PLC Alsmart universal programmable unit capable of controlling all of a retail store’s electronics, including the refrigeration, HVAC and lights, to maximize operational efficiency.

• The unit’s open protocol offers connection compatibility with third-party equipment.
• It works with all refrigerants, including CO₂ and flammable natural refrigerants.
• “With this unit, we can analyze flow chains to inform store owners if they can shut off the refrigeration to take advantage of a utility incentive without damaging food,” Groff said. “If there is a potential issue, it kicks the refrigeration back on.”

Get smart: Danfoss’s “smart store” in Nordborg, Denmark, produces more energy than it consumes with an integrated CO₂ system providing refrigeration, heating and cooling.

• The store incorporates Danfoss’s heat recovery unit for comfort heating and domestic hot water. Excess heat is sold to the local district heating system.
• According to Groff, Danfoss is discussing building another smart store, but he did not provide additional details.

Quotable: “There is no justifiable reason not to go to CO₂ [refrigeration],” Groff said. “We have the components and the ability to manage the system correctly. It’s not about maximizing the efficiency of any one component but about maximizing it all together.”

“There is no justifiable reason not to go to CO₂.”

Dean Groff, Field Services Manager at Danfoss

This article has been updated with new information on the number of cases the condensing unit can support.