CO2 Refrigeration Systems (R744)

Highly Efficient Cooling and Heating from a Single System

Carbon dioxide (R744) has revolutionized refrigeration technology. What was once considered an exotic high-pressure application is now the state of the art for future-proof supermarkets, logistics centers, and industrial applications. At cold.world ENGINEERING, we design state-of-the-art CO₂ combined systems that thermodynamically and intelligently integrate cooling and heating—for maximum energy efficiency and the complete elimination of direct F-gas emissions.

R744: The Refrigerant for High Thermodynamic Demands

CO₂ is nonflammable, nontoxic, and chemically inert. This makes it the ideal alternative to synthetic refrigerants affected by F-gas bans and provides safe solutions in situations where ammonia cannot be used due to local regulations.

• The “Heat Champion”: No other refrigeration technology is as well-suited for heat recovery as CO₂. Due to the high temperature on the high-pressure side (gas cooler operation), process water or heating energy can often be provided highly efficiently as a byproduct of refrigeration.
• Safety Class A1: Since CO₂ is neither toxic nor flammable, the safety and structural requirements for the installation site are often significantly less stringent than those for toxic or flammable refrigerants.
• Compact Design: Thanks to the extremely high volumetric cooling capacity and operating pressures, piping systems and compressors can be designed to be very compact.
• Regulatory Future-Proofing: With a direct global warming potential (GWP) of 1, R744 is fully compliant with the F-Gas Regulation and offers operators long-term planning certainty without phase-down risks.

Our Expertise in CO2 Technology

Designing CO2 systems requires a deep understanding of thermodynamics, as these systems often operate in the “transcritical” range. We have a thorough grasp of the technology:

1. Transcritical booster systems

We design systems that efficiently handle both standard refrigeration (NK) and deep-freeze refrigeration (TK) in a single circuit. Ideal for food logistics and online retail.

2. Increased Efficiency Through Ejectors and Parallel Compression

To ensure that CO2 systems operate with high efficiency even at high outdoor temperatures, we rely on modern technologies such as ejectors (multi-ejector technology) and parallel compressors. This significantly reduces electricity consumption, even in the height of summer.

3. Integrated Heating and Cooling Systems

We don’t view your refrigeration system in isolation. We integrate the CO2 system into your building services so that the waste heat from the cooling process can be used for heating, hot water, or process heat. This often eliminates the need for a gas boiler.

Typical Applications for Our CO₂ Solutions

• Food Retail & Supermarkets: The proven standard for CO₂.
• Logistics Centers (E-commerce): Large, efficiently refrigerated distribution centers for fresh and frozen goods.
• Industrial Process Refrigeration: Wherever plant safety (Class A1) is the top priority.
• Air Conditioning: Use of CO₂ chillers for building cooling.
• Commercial heat pumps: Ideal for large temperature differentials (high flow temperatures).

Frequently Asked Questions About CO2 Systems

Is high CO2 pressure dangerous? R744 systems operate at pressures of up to 120 bar (on the high-pressure side). That may sound like a lot, but thanks to modern steel piping and certified components (K65 pipes, high-pressure valves), it is technically fully manageable and safe. Our design ensures the highest level of operational safety.

Is CO2 also effective in the summer? From a thermodynamic perspective, transcritical operation is more energy-intensive at high outdoor temperatures. Although this physical effect is now significantly mitigated by the use of parallel compressors and ejectors, power consumption on hot midsummer days is often higher than with conventional refrigeration systems. For economic evaluation, however, it is not the isolated peak load in midsummer that is decisive, but rather the annual energy balance (annual coefficient of performance) of the entire system. During the long transitional and winter months, CO₂ systems operate with above-average efficiency. Furthermore, when the enormous potential of heat recovery is factored into the analysis, properly designed CO₂ systems achieve outstanding efficiency values throughout the operating year.

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