Although CO₂ refrigeration has more commonly been deployed in large, centralized booster systems, the case for CO₂ distributed systems is getting stronger. Recent advancements in CO₂ scroll compression technology have expanded the potential of R-744 in smaller, distributed refrigeration units. This innovation has helped enable commercial refrigeration equipment manufacturers to develop the next generation of optimized, efficient, and reliable CO₂ distributed units in North America.  

For large- and small-format retailers seeking all the scalability and efficiency benefits of distributed refrigeration — while supporting sustainability targets and complying with refrigerant regulations — a new era of distributed CO₂ refrigeration has arrived in North America. 

Distributed System Advantages 

Compared to traditional centralized direct-expansion systems — where large compressor racks supply low- and medium-temperature cooling throughout a store — distributed systems have often been specified for their flexibility, performance, and efficiency advantages.  

This involves deploying mini-rack systems in strategic locations — either on the sales floor, in a back room, or roof — closer to a row of display cases. For example, five to six smaller refrigeration systems may be located around a store instead of having two to three large racks in a machine room. For small-format operators, one or two distributed systems may be all that is needed.  

Today, this remains a popular option for many large retailers, regardless of refrigerant type. Even with legacy, high-GWP refrigerants, this distributed approach offers multiple benefits over centralized systems: 

• Smaller system size reduces refrigerant charge and piping 

• Reduced piping/connections lower annual leak rates, and cut carbon emissions 

• Suction lines can group fixtures with similar saturated suction temperatures, allowing them to operate at higher SSTs, which improves system efficiency 

• Distributed refrigeration reduces downtime and improves redundancy, eliminating the risks of centralized, full-system failure and associated product loss 

• Heat recovery and reclaim can be leveraged for HVAC system heating and dehumidification. 

The refrigerant transition is also driving retrofit and remodel decisions that may favor distributed refrigeration architectures. As operators evaluate end-of-life strategies for their existing centralized HFC systems, distributed systems present opportunities to phase out underperforming sections of their systems and replace them with lower-GWP options. 

All these advantages apply to CO₂ distributed systems, with the added sustainability benefits that include: 

• Low GWP of 1 

• Non-flammable and non-toxic (i.e., A1 classification) 

• Globally accepted and applied as a future-proof, next-gen refrigerant 

• Higher potential for heat reclaim than HFC systems. 

Scalable Sustainability 

The barriers to developing CO₂ distributed refrigeration units have been mostly technological. First, it’s a matter of scale: compressors used in large, centralized CO₂ systems are simply oversized for use in distributed systems. 

Second, CO₂ compression must be able to operate at the high pressures that occur, especially in a CO₂ booster system’s transcritical mode, which happens any time ambient temperatures reach above 75 °F (assuming the system uses a dry gas cooler).  

The next generation of smaller-footprint CO₂ transcritical-rated compression is now ready to be explored. Copeland has cleared technological hurdles with the launch of its transcritical CO₂ scroll compressor platform, which can be applied in distributed CO₂ booster system architectures. It can also be used in a single-compressor, medium-temperature system, such as a condensing unit.  

Copeland transcritical CO₂ scroll compressors are available in fixed- and variable-speed configurations and feature dynamic vapor injection technologies. Variable speed enables precise capacity matching and efficiency, leveraging a brushless permanent magnet motor design and optimized drive pairing. Variable-speed compression technology is more efficient than induction motor/drives in low-load scenarios and can overspeed to match the demands of high-load conditions. 

A new era of distributed CO₂ refrigeration has arrived in North America, driven by the need for greater design flexibility and lower-impact refrigerants. Innovative transcritical CO₂ scroll compressors with DVI technology are helping make distributed systems simpler and more scalable, with all the sustainability benefits of the natural refrigerant CO₂.