Zero Zone is proud to be a key contributor to Walgreens’ first-ever net-zero energy store in Evanston, Illinois, a project that sets a new benchmark for sustainable retail. At the core of this achievement is our Genesys™ CO₂ Transcritical Rack System, an integrated solution that delivers refrigeration, HVAC, and hot water—all powered primarily by onsite solar energy.
Unveiled at the ATMO America Summit, this installation showcases how our rack system supports Walgreens’ ambitious carbon reduction goals while maintaining high performance and reliability. The system’s transcritical CO₂ technology not only reduces greenhouse gas emissions but also improves energy efficiency across the store’s operations.
Key Rack System Highlights:
- Integrated design: Combines refrigeration, heating, and cooling in one compact rack system.
- Natural refrigerant: Uses CO₂, a low-GWP refrigerant, aligning with Walgreens’ sustainability goals.
- Energy synergy: Works in tandem with solar panels and battery storage to minimize grid dependency.
- Scalable innovation: Demonstrates how Zero Zone rack systems can support net-zero strategies for large-scale retail.
This project is a testament to how Zero Zone’s engineering and innovation are helping retailers transition to cleaner, smarter energy solutions.
Read the Full Article to see how Our Rack System is Powering the Future of Sustainable Refrigeration.
CO₂ refrigeration systems are becoming the go-to modern, eco-friendly solution because environmental regulations are tightening, and as a result, energy efficiency is taking priority in commercial and industrial refrigeration operations. However, CO₂ refrigerant systems aren’t just a drop-in replacement for traditional refrigerants. Instead, they come with a unique set of considerations that ultimately impact performance, reliability, and long-term ROI.
In this blog, we’ll break down the basics of CO₂ (carbon dioxide) refrigeration in clear, practical terms. Whether you’re upgrading equipment, building a new facility, or exploring sustainable refrigeration options, this guide will help you understand what makes CO₂ systems different—and how to maximize their potential in your operation.
Why Choose CO₂ as a Refrigerant?
CO₂, also known as refrigerant R-744, is gaining momentum in the refrigeration industry for good reason:
- Low Environmental Impact: CO₂ has a Global Warming Potential (GWP) of just 1. In contrast, traditional refrigerants like R-404A have a GWP over 3,900.
- High Energy Efficiency: In the right conditions, CO₂ systems can outperform conventional refrigeration systems, particularly in cooler climates.
- Regulatory Compliance: CO₂ systems future-proof your facility by aligning with evolving environmental and refrigerant phase-down regulations.
However, CO₂ is not without its challenges. Specifically, system design, pressure management, and climate adaptability require careful consideration.
Key Differences: How CO₂ Refrigeration Systems Operate
CO₂ refrigeration systems function differently than traditional systems, and understanding these differences is key for informed decision-making.
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Higher Operating Pressures
- CO₂ operates at much higher pressures than other refrigerants. Although this might sound alarming, today’s systems are built with specialized components designed to handle these conditions safely and reliably. Proper engineering and installation are essential.
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Two Modes of Operation: Subcritical and Transcritical
- Subcritical Mode: In cooler climates or during colder months, CO₂ behaves like traditional refrigerants—operating at manageable pressures with efficient heat exchange.
- Transcritical Mode: In warmer environments, CO₂ enters a supercritical state, where it no longer behaves as a typical liquid or gas. This mode requires more advanced system controls and heat rejection strategies to maintain efficiency.
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Unique Thermodynamic Properties
- CO₂ has a triple point and critical point that impact system design. These characteristics influence how heat is removed and, furthermore, how pressure is managed across the system, particularly in variable climates.
- Triple Point: The temperature and pressure where CO₂ can exist as a solid, liquid, and gas.
- Critical Point: The temperature where CO₂ becomes a supercritical fluid.
Commercial Refrigeration and the AIM Act
The American Innovation and Manufacturing (AIM) Act, enacted in December 2020, has brought significant changes to the commercial refrigeration industry. As we navigate through 2025, the first set of restrictions under the AIM Act are now in effect. These restrictions aim to phase down the production and consumption of hydrofluorocarbons (HFCs) by 85% by 2036. Consequently, these regulations are crucial for reducing greenhouse gas emissions and transitioning to more environmentally friendly refrigerants.
Technology Transition Rule
One of the key aspects of the AIM Act is the Technology Transition Rule, which impacts the repair and servicing of refrigerated display cases. The rule specifies that repairs are permissible unless they result in the creation of a new system. Therefore, while existing display cases can continue to operate and be serviced, certain extensive repairs may be restricted. For instance, assembling a system for the first time from used or new components, increasing the cooling capacity of an existing system, or replacing 75% or more of evaporators and 100% of the compressor racks, condensers, and connected evaporator loads are considered new installations. Importantly, these replacements are cumulative—meaning all prior repairs are counted toward the threshold when evaluating whether a system has effectively been replaced.
Ensuring Compliance
Understanding these repair restrictions is essential for businesses to ensure compliance and avoid potential penalties. As we move forward, staying informed and adapting to these regulations will be key to maintaining operational efficiency and environmental responsibility. This blog will help navigate the repair restrictions of refrigerated display cases.
Last month, we discussed the ways in which industrial and commercial refrigeration systems can achieve greater energy efficiency using modern components.
This month, we will delve into the advancements in commercial reach-in freezers and coolers, commonly known as refrigerated display cases within the industry. We will explore how these units have been optimized for efficiency and effective cooling with the integration of the latest refrigeration technology.
As energy costs rise, regulations evolve, and consumer demand for environmentally friendly solutions increases, evaluating your current commercial or industrial refrigeration system for a potential upgrade increases in importance. When considering an upgrade, several factors – such as the current condition of your equipment, maintenance costs, energy efficiency, and refrigerant type must be evaluated. Each of these factors play a role in determining the cost effectiveness of an upgrade.
Now that we have crossed into 2025, the first restrictions of the American Innovation and Manufacturing (AIM) Act are now in effect. The AIM Act of 2020 allows the EPA to restrict the production, import, and use of hydrofluorocarbons (HFCs). HFC refrigerants have a high global warming potential (GWP) and are being phased down by 85% through 2035.
The Refrigerants allowed by the AIM Act are not direct substitutes for HFC refrigerants. Refrigeration systems require different components, piping and programming with each refrigerant. The performance of refrigeration systems is influenced by the external ambient temperatures.
Equipment installed before restrictions go into effect are allowed to maintain operation throughout their useful life. This includes service, parts, and refrigerant. However, the availability of each is dependent on the manufacturer.
Retrofitted equipment and new installations have their own regulations and definitions. Retrofitted equipment, replacing at least 75% or more of the evaporators and 100% of the compressor racks, condensers, and connected evaporator loads of an existing system, will need to follow the restrictions for a new installation. For more information on the AIM Act and state regulations, visit our Refrigerant Regulations webpage.
Refrigeration Upgrades: Enhancing Energy Efficiency and Reducing Costs
Refrigeration systems are among the most energy-intensive systems in operation. Upgrading them can significantly increase their energy efficiency and reduce operational costs. Refrigeration Upgrades are essential for businesses looking to optimize their energy consumption and improve their bottom line.
Factors to Consider Before Upgrading
This article explores several factors that need to be considered before upgrading your industrial or commercial refrigeration system. These factors include:
- Energy Efficiency: Upgrading refrigeration systems can lead to substantial improvements in energy efficiency. Modern systems are designed to consume less power while maintaining optimal performance.
- Operational Costs: By enhancing energy efficiency, businesses can reduce their operational costs. Lower energy consumption translates to lower utility bills and overall cost savings.
- System Reliability: Newer refrigeration systems are built with advanced technology that ensures higher reliability and fewer breakdowns. This reduces maintenance costs and downtime.
- Environmental Impact: Upgraded systems often use eco-friendly refrigerants and technologies that minimize environmental impact. This aligns with sustainability goals and regulatory requirements.
Benefits of Refrigeration Upgrades
Investing in refrigeration upgrades offers numerous benefits:
- Improved Performance: Upgraded systems provide better cooling performance, ensuring that products are stored at the optimal temperature.
- Enhanced Control: Modern refrigeration systems come with advanced control features that allow precise temperature management and monitoring.
- Long-Term Savings: Although the initial investment may be significant, the long-term savings in energy costs and maintenance make it a worthwhile investment.
Real-World Example
discusses the impact of refrigeration upgrades in his article. He highlights how businesses have successfully reduced their energy consumption and operational costs by implementing modern refrigeration solutions. These upgrades not only improve efficiency but also contribute to a more sustainable operation.
Learn More
To delve deeper into the factors and benefits of refrigeration upgrades, read the full article by on Refrigerated and Frozen Foods
This comprehensive guide provides valuable insights into how refrigeration upgrades can transform your business.
To learn more about what Refrigeration System is right for your application, visit our systems page.
AIM Act Refrigerants: Driving Sustainable Business Practices
AIM Act Refrigerants are rapidly gaining priority as rising energy costs, evolving regulations, and increasing consumer demand for environmentally friendly solutions drive change. Consequently, sustainable business practices have become essential. In the refrigeration industry, the choice of refrigerant directly affects both energy costs and regulatory compliance. Therefore, this blog will explore the advantages and disadvantages of low-global warming potential (GWP) refrigerants, including Natural and Hydrofluoroolefin (HFO) options.
Flexibility and Durability of Hybrid™ Merchandisers
The Hybrid™ merchandiser offers the flexibility of a self-contained display case while maintaining the durability and sales capability of those in large supermarkets. Each Hybrid™ merchandiser inherits the traits of its remote counterpart and has all the necessary refrigeration components mounted on top of the display case. These cases require minimal effort to install. After connecting the remote condensing unit to the display case, they are ready to be energized for operation. With medium- and low-temperature options, you can display beverage, bakery, dairy, deli, floral, frozen food, meat, produce, or seafood products in an environment that will keep them fresh.
Benefits for Stores of Any Size
Zero Zone Hybrid™ merchandisers provide benefits for a store of any size. They allow small format stores to effectively and efficiently use their floorspace for merchandising products rather than taking up valuable real estate for the refrigeration system. Additionally, large format retailers can add a Hybrid™ merchandiser to the sales floor without increasing the installed system’s load or the need for additional refrigeration piping.
A walk-in cooler turns into an oasis during the summer months. While this may bring you relief, it adds stress to your industrial or commercial refrigeration system. The efficiency of any refrigeration system drops as the ambient temperature increases. Pressure within the system also increases, putting strain on the entire system. For areas with warmer climates, this happens for a longer period of time during the year. There are many ways to mitigate stress and heat in your system, but which one works best for your application?
