Vitalis Roxsta™ G6 R744 (CO2) rack with 4 MT and 3 LT Dorin compressors, plus proprietary oil management innovations
The "Smoothest-Running Rack"
Inside the selection and installation of a Vitalis R744 (CO2) refrigeration system for a Southern California supermarket
Project Snapshot
End user: Northgate González Market (aka Northgate Market)
Designer & contractor: Classic Refrigeration
Application: Food retail / supermarket
Location: La Mirada, California
System: Vitalis Roxsta™ G6 R744 (CO2) rack with 4 MT and 3 LT Dorin compressors, plus premium oil management technologies
Capacities:
Medium-temperature: 501 kBTU/h (41.75 TR) @ 21°F
Low-temperature: 80 kBTU/h (6.6 TR) @ -26°F
“We have a high level of confidence in the long-term performance. The build quality is solid, and the way the system handles oil and maintains stable conditions should translate into less wear on compressors and fewer service issues over time. That’s what matters to us—systems that don’t create callbacks.”
—Ray Kelly, Senior Applications Engineer, Classic Refrigeration
The Challenge: Future-Proof Refrigeration for a Complete Store Renovation
When Northgate Market decided to remodel an existing store (previously operated by a different grocer) for one of its newest locations, the scope was more ambitious than a simple equipment upgrade. This project encompassed a total overhaul of the refrigeration infrastructure.
The primary challenges were three-fold: complying with California's stringent regulatory requirements, staying on budget, and meeting a strict store-opening timeline.
In food retail, refrigeration system reliability is also a non-negotiable requirement. Because many grocery items are perishable, refrigeration is critical to daily operations. Refrigerated food can spoil rapidly if not kept at the proper temperatures. So uptime is arguably the most important metric in retail refrigeration. If a system failure occurs and is not resolved quickly, the resulting spoilage can lead to massive financial losses and severe reputational damage among a store's customers.
Why F-Gas Systems Were Not Considered
Designed against the backdrop of the federal AIM Act and even stricter state-level rules administered by the California Air Resources Board (CARB), this project had to ensure regulatory compliance with both current and foreseeable refrigerant regulations.
Traditional F-gas refrigerants like R404A and R507A are no longer viable options as they exceed allowed global warming potential (GWP) thresholds for new stationary systems. And while high-GWP HFCs are being phased out, lower-GWP A2L refrigerants (mildly flammable HFOs and HFC/HFO blends) also come with future phase-down risks due to their contribution to PFAS pollution and GWP values that are often still high relative to ultra-low-GWP natural refrigerants.
The Decision: An R744 (CO2) Solution From Vitalis
R744, a natural refrigerant, is becoming the default solution for many commercial and industrial applications in California due to corporate sustainability targets, the state's aggressive GWP limits, the potential for future phase-downs of synthetic F-gas replacements, and flammability concerns with other alternatives.
With a GWP of 1, no flammability, and no PFAS liabilities, R744 minimizes regulatory risk, stabilizes lifecycle costs, and delivers exceptional performance. For long-term refrigeration assets, these factors make R744 one of the most secure and economically sound refrigerant options available today for supermarkets and other food retailers.
For Northgate Market, R744 was the clear refrigerant of choice. For Classic Refrigeration, the designer and contractor for this project, that meant finding an original equipment manufacturer (OEM) capable of fulfilling this challenge and, ideally, becoming a reliable long-term partner for additional projects.
Classic Refrigeration’s decision to select Vitalis as the OEM was driven by Vitalis' relationship-oriented approach to business and technical expertise, bolstered by the extensive European R744 experience of Vitalis' sister company TEKO Refrigeration.
Unlike larger manufacturers that often take a more rigid "my way or the highway" approach, Vitalis demonstrated the nimbleness required to meet market demands and work on customizing a solution. This was critical given Classic Refrigeration's well-established relationship with Northgate Market and the priority put on trust, quality, and support in the product.
“Working with Vitalis has been a strong experience,” says Ray Kelly of Classic Refrigeration. “They’re responsive, collaborative, and open to feedback from the field. You can tell they understand CO2 systems, and they back up their equipment with real support. That makes a big difference when you’re installing and servicing these systems.”
Vitalis' "hand-in-hand" collaboration lasted from initial concept through construction and installation.
The System: Transcritical R744 Refrigeration With Proven Oil Management Innovations
The heart of the store's refrigeration infrastructure is an indoor Vitalis Roxsta G6 rack featuring:
4 MT Dorin compressors for 41.75 TR of medium-temperature cooling capacity and an evaporating temperature of 17°F
3 LT Dorin compressors for 6.6 TR of low-temperature cooling capacity and an evaporating temperature of -26°F
Heat reclaim
Alfa Laval heat exchangers
Danfoss controls with system manager
Adiabatic gas cooler
In addition to these high-quality components, the system includes proven oil management innovations for superior performance and reliability:
Compressor Shield™ technology, a patent-pending heat exchanger configuration with intelligent control for maintaining stable MT temperatures, lower discharge temperatures, minimal oil degradation and improved lubrication
AUthentic oil management technology, featuring advanced oil separator cartridges that prevent the risk of fiber contamination within the system from deformation or blowouts under the higher pressures typical of transcritical CO2 operation
Together, these components deliver:
Extended compressor lifespan
Improved system stability
Enhanced reliability and operational safety
Better system monitoring
Increased uptime and smoother system restarts after power outages
“We have a high level of confidence in the long-term performance,” says Kelly. “The build quality is solid, and the way the system handles oil and maintains stable conditions should translate into less wear on compressors and fewer service issues over time. That’s what matters to us—systems that don’t create callbacks.”
The Feedback: Post-Installation Observations
The Roxsta G6 system was delivered on time and on budget, ensuring the store opening remained on schedule.
“Installation was straightforward,” says Kelly. “The racks come well-organized and clearly labeled, which makes a big difference on-site. Everything is accessible, and you’re not fighting the layout. Commissioning went smoothly as well—systems came online without a lot of troubleshooting, and we were able to get to stable operation quickly.”
Following commissioning, Classic Refrigeration reported being pleased with the technology and high level of performance. In a testament to the engineering quality, Classic described the system as the "smoothest-running rack" they had ever seen in their many years of operation.
One particular aspect of the system that stood out was the significant reduction in the amount of oil required due to the Vitalis AUthentic oil management technology, including the oil separator cartridge.
As Kelly says, “From our perspective, the system just runs stable. Suction conditions are consistent, and we’re not chasing issues the way you sometimes have to on other CO2 racks. Oil management is clearly dialed in—there’s very little migration into the field, which keeps evaporator performance where it should be. Compared to a traditional oil system, using the Vitalis AUthentic oil cartridge we were able to remove around 6 gallons of oil from the total system volume. Overall, it’s a well-thought-out design that translates into reliable day-to-day operation.”
Looking ahead, the system is expected to deliver lower overall operational expenses and require fewer service calls compared to other R744 racks on the market.
“We have a high level of confidence in the long-term performance,” says Kelly. “The build quality is solid, and the way the system handles oil and maintains stable conditions should translate into less wear on compressors and fewer service issues over time. That’s what matters to us—systems that don’t create callbacks.”
The financial case for the system is further strengthened by Northgate Market's participation in the State of California's F-gas Reduction Incentive Program (FRIP), which provides a rebate for adopting ultra-low-GWP refrigeration technologies.
The food retail market moves quickly, and this project underscores the value of working with Vitalis to customize solutions and meet demanding timelines without compromising long-term durability.