Refrigeration system is the core equipment for supermarket freshness operation. Traditional HFC refrigerants are characterized by high leakage, high carbon emissions, high compliance risk, and rising operation and maintenance costs. Driven by the tightening of environmental control, cost reduction and efficiency and ESG transformation, a large number of supermarkets are replacing their refrigeration systems with environmentally friendly and efficient carbon dioxide (R744) refrigeration systems.
This article will deeply analyze the core reasons for supermarkets to replace the carbon dioxide refrigeration system, popularize the working principle, core advantages and pain points of CO₂ refrigeration, and analyze the applicable scenarios and future development trend of this technology in combination with the landing data of the global industry in 2025 to provide professional references for the upgrading of HVACR in the retail industry.
What Is a CO2 Refrigeration System?
Carbon dioxide (R744) refrigeration system is a vapor compression refrigeration equipment with natural carbon dioxide as the medium. It replaces traditional synthetic HFC refrigerants such as R404A and R134a, and has become the mainstream green energy-saving solution in the commercial refrigeration field by virtue of its excellent environmental attributes and stability, and is widely used in supermarkets, cold-chain warehousing, food processing, and other types of commercial and industrial scenarios.
Core Characteristics
CO₂ has become the preferred medium for retail refrigeration because of its excellent environmental and safety attributes, as well as its outstanding heat transfer performance:
- Global Warming Potential (GWP) = 1, almost no greenhouse effect;
- Ozone layer depletion potential ODP = 0, will not destroy the atmospheric ozone layer;
- Safety grade A1, non-toxic, non-combustible, suitable for densely populated supermarket business scenarios.
In addition, CO₂ high heat transfer efficiency, volumetric refrigeration capacity, can be matched with smaller sizes of pipelines and compressors, streamlining the structure of the equipment. The only significant feature is that the operating pressure is much higher than the traditional HFC system, and the pressure on the high pressure side can reach 100-140 bar, which requires higher requirements for equipment materials and installation techniques.
Refrigeration Working Cycle
CO₂ refrigeration system follows the classic vapor compression refrigeration cycle, the overall process is similar to the traditional refrigeration system, but because of the core differences in media characteristics, the complete process is divided into four steps: low-pressure liquid CO₂ absorbs the heat of the supermarket cold storage, display cabinets in the evaporator, evaporates into a gaseous state;
The compressor compresses the gaseous CO₂ into a high temperature and high pressure state; through the gas cooler (transcritical mode instead of the traditional condenser) to the outside world to dissipate the heat; and finally by the expansion valve to reduce the pressure and cooling, and revert to a low-temperature, low-pressure liquid state, and return to the evaporator to work in a cycle.
Core Technology Distinction
Sub-critical mode runs below the CO₂ critical parameter (31.1℃, 73.8bar), the gas can be condensed and liquefied normally, the working principle is the same as that of the traditional refrigeration system, and it is mostly used in cold areas or compound refrigeration scenarios.
Trans-critical mode running above the critical parameters, no obvious gas-liquid phase change in the heat dissipation phase, with supercritical fluid state heat dissipation, is the mainstream operation mode of supermarket CO₂ system in warm areas, with flash tanks, high-pressure control valves to achieve stable switching of working conditions.
At present, the most commonly used in supermarkets is the pressurized CO₂ refrigeration system, through multi-stage compression and graded temperature control, respectively adapted to the low-temperature freezing and medium-temperature refrigeration scenarios, with flash tanks to achieve gas-liquid separation, significantly improving the system’s operating efficiency.
Why Supermarkets Are Moving Away from Traditional Refrigerants
Supermarket refrigeration equipment is in continuous operation all year round, with a large number of equipment and long pipelines, making it the hardest hit area for commercial refrigerant consumption and leakage.
The inherent shortcomings of traditional HFC refrigerants, coupled with multiple pressures from policy, cost and market, are forcing the entire retail industry to accelerate the transition to CO₂ natural refrigeration solutions.
High Global Warming Potential (GWP) and Climate Impact
Countries around the world have introduced HFC refrigerant phase-out and reduction policies, forming an irreversible industry trend, non-compliant enterprises will face multiple risks such as fines, equipment deactivation, brand reputation damage.
The EU F-Gas regulations prohibit high GWP refrigerants from 2025 and standards continue to tighten, the U.S. AIM Act deadline to significantly reduce HFC production capacity and application, double control caused by the shortage of HFC consumables, the price skyrocketed.
Global head retail brands, including Walmart, Orazi, Carrefour, have released natural refrigerant transition planning, CO₂ refrigeration system as the strongest compliance program, become the core choice of supermarkets to avoid policy risks and achieve long-term compliance.
Stringent Environmental Regulations
Traditional supermarkets commonly used R404A, R134a and other HFC refrigerants, the greenhouse effect of the destructive power is amazing, of which the GWP value of R404A is as high as 3,922, which is nearly 4,000 times that of CO₂.
Supermarket refrigeration system piping is complex, more joints, the average annual refrigerant leakage is extremely large, the annual carbon emissions of HFC leakage of a single store, equivalent to the annual emissions of hundreds of motor vehicles, refrigeration carbon emissions can account for more than 50% of the total carbon emissions of the supermarket.
CO₂ refrigerant GWP value is only 1, almost no additional greenhouse effect, can cut the direct carbon emissions from the root of the supermarket, help stores to complete the carbon neutral, ESG assessment indicators.
Rising Costs of Traditional Refrigerants
Influenced by the global HFC quota reduction and capacity control, the price of traditional refrigerants has increased more than three times in recent years, and the stability of supply is extremely poor. Supermarket refrigeration system has a normalized leakage problem, the need for frequent replenishment of refrigerant, the long-term accumulation of the cost of consumables has become an important operational burden on the store.
Compared with this, CO₂ take a wide range of materials, sufficient reserves, low prices, not subject to international quota policy restrictions, no need to worry about price increases, shortage of supplies, can fundamentally reduce the cost of refrigerant supplies supermarkets.
Corporate and Market Pressures
Nowadays, consumers and the capital market are paying more and more attention to the green management ability of enterprises, and the image of green and low-carbon stores has become one of the core competitiveness of retail brands. The head of supermarket chains have layout of natural refrigeration technology to create a low-carbon store benchmark.
At the same time, as the HFC phase-out policy continues to fall, the traditional refrigeration equipment will be gradually eliminated, the layout of CO₂ refrigeration system in advance, you can avoid the risk of large-scale transformation, equipment scrapping brought about by the assets stranded, to seize the industry’s green transformation opportunity.
Major Benefits of CO2 Refrigeration Systems for Supermarkets
Environmental Sustainability
As a natural refrigerant, CO₂ has no risk of ozone depletion and the greenhouse effect is close to zero. After replacing the traditional HFC system, supermarkets can significantly reduce direct carbon emissions, quickly fulfill the government’s environmental protection assessment and corporate ESG rating requirements, fit the trend of green upgrading in the supermarket industry, and help brands create a low-carbon, environmentally friendly market image.
Energy Efficiency
Modern CO₂ refrigeration system with injectors, parallel compression, adiabatic gas cooler and other core technologies, refrigeration coefficient of performance (COP) is excellent, and can realize on-demand frequency conversion speed control, to adapt to the supermarket refrigeration load fluctuations during day and night, off-peak seasons.
Compared with the traditional HFC equipment, CO₂ system can realize more than 10% power saving effect. At the same time, the waste heat generated by the system can be recycled and utilized for store heating and hot water supply, further reducing the overall energy consumption and providing significant long-term energy-saving benefits.
Safety and Non-Toxicity
Supermarkets are densely populated public places, and equipment safety is of paramount importance; CO₂ refrigerant is non-toxic, non-flammable, and has no risk of explosion or poisoning, which completely avoids the safety hazards of partially synthetic refrigerants and propane refrigerants, and it is perfectly adapted to the safety standards of the food retailing industry, safeguarding the personal safety of the customers and the store staff, and lowering the risk of equipment safety accidents.
Operational Versatility
CO₂ refrigeration system has a wide range of temperature adaptability, and can operate stably and efficiently in cold and mild climates, and after technical optimization, it can maintain good working conditions in high-temperature tropical and subtropical regions.
At the same time, the system can be customized according to the supermarket layout and refrigeration demand, taking into account the diverse needs of low-temperature preservation in display cabinets and deep freezing in cold storage, and adapting to different sizes of supermarkets and stores in different regions.
Long-term Compliance
In the face of the global escalating HFC control policy, CO₂ as a zero low-carbon natural refrigerant, is not subject to all kinds of phase-out policy restrictions. Supermarkets layout CO₂ refrigeration equipment, can be a one-time solution to long-term compliance issues, without the need to frequently follow up the policy iterative transformation of equipment, refrigeration equipment to realize the long-term preservation of the value of the investment, to avoid policy changes brought about by the business risks.
Challenges of CO2 Refrigeration Adoption
Despite the outstanding advantages of CO₂ refrigeration, but the popularization of the industry there are still certain thresholds, mainly focused on technology, cost, operation and maintenance levels, but also part of the small and medium-sized supermarkets to wait and see the core reasons.
- Initial investment costs are high: CO₂ system high-pressure operating characteristics, need to be matched with stainless steel tubing, high-pressure compressor and other special accessories, equipment and installation costs than the traditional HFC system is higher than 10% -20%, the old store transformation costs are higher for small and medium-sized supermarkets budget threshold is high.
- High-temperature conditions native efficiency short board: ambient temperature over 25-30 ℃, the transcritical CO₂ system cooling efficiency decline, energy consumption rose slightly, can be properly resolved through the injector, parallel compression, adiabatic cooling and other technical optimization.
- Shortage of professional operation and maintenance personnel: CO₂ high-pressure system commissioning, maintenance difficulties far beyond the traditional equipment, the need for special licensed technicians. At present, there is a large gap between professional technicians in the industry, especially in the sinking market, which easily leads to high operation and maintenance costs, slow maintenance response and other issues.
- Old stores are difficult to transform: CO₂ system on the pipeline, pressure control, machine room layout requirements are stringent, the traditional old equipment can not be adapted. Remodeling requires large-scale dismantling of the machine, changing the piping, and re-commissioning, with a long construction period, a large impact on business, and a much higher cost of remodeling than that of a new store.
Where CO2 Refrigeration Systems Are Being Used
After more than ten years of technology iteration, CO₂ refrigeration system has changed from a new technology solution to the mainstream choice of global retail refrigeration, and the penetration rate of each regional market continues to climb.
Europe
Europe is the earliest region to popularize CO₂ refrigeration, with mature technology application and rich experience on the ground. 2025 data shows that more than 90,700 retail stores in Europe have been equipped with transcritical CO₂ refrigeration systems, with a market penetration rate of 30%. Germany, the United Kingdom, Norway, Denmark and other countries have the highest degree of penetration, Tesco, Orazi, Carrefour and other head of the chain brands have realized a large area of full coverage of stores.
North America
Driven by the U.S. AIM Act and corporate carbon neutral policy, the North American market has seen explosive growth in the past two years. 6,360 supermarkets, convenience stores and cold chain factories in the U.S. and Canada have landed on the CO₂ refrigeration system in 2025, an increase of 28% compared with 2024, of which more than 5,120 supermarkets accounted for the proportion of stores. U.S. supermarket CO₂ refrigeration penetration rate will exceed 22% in 2028.
Asia-Pacific
Japan is the leader in the Asia-Pacific region, with a total of more than 14,930 sets of CO₂ refrigeration equipment, covering a large number of convenience stores and supermarkets.
New Zealand supermarket penetration rate of 22%, coles, Woolworths and other mainstream Australian chains continue to increase the layout. China and Southeast Asia market is in its initial stage, gradually transitioning from traditional refrigeration to natural refrigeration solutions, with huge growth potential.
Other Emerging Regions
Latin America, the Middle East and Africa market started relatively late, but has been steadily expanding in recent years. Jordan, Brazil, Turkey and other countries have landed a number of supermarkets CO₂ refrigeration benchmarking projects to promote the globalization of the popularity of the technology continues to take shape.
Is CO2 Refrigeration Right for Every Supermarket?
CO₂ refrigeration system is a high-quality upgrade program for retail refrigeration, but it is not suitable for all store scenarios, supermarkets need to rationally select the type according to their own situation.
When CO₂ Refrigeration Is a Strong Fit
CO₂ refrigeration system has a very high adaptability in many types of supermarket scenes, can give full play to the energy saving, compliance, long-term operational advantages, investment cost-effective and outstanding, the specific adaptability of the scene is categorized as follows:
- Newly built and large-scale renovation stores: high-pressure refrigeration pipelines, machine room layout and equipment configuration can be planned in advance in the decoration and infrastructure stage, without having to accommodate the old equipment, eliminating the need for remodeling and dismantling, rewiring of the additional costs and construction losses, the system adaptability and landing the best results.
- Large supermarket chains: national chain brands have sufficient funds, large store volume, through large-scale procurement, batch landing way to dilute the cost of equipment and technology upgrades, maximize the long-term operational value of the CO₂ system, suitable for standardization and popularization of landing.
- Temperate and frigid zone area stores: These areas have appropriate environmental temperatures, which can perfectly avoid the high-temperature efficiency shortcomings of the CO₂ transcritical system, and the equipment runs stably and efficiently throughout the whole process, with excellent energy-saving effect and operational stability.
- Enterprises focusing on ESG and green brand building: Relying on the zero ozone depletion and extremely low carbon emission characteristics of CO₂ refrigerant, they can quickly realize low-carbon business objectives, efficiently complete environmental protection assessments and ESG ratings, and further enhance the credibility of the brand’s green credibility and market competitiveness.
- Stores with comprehensive energy consumption optimization needs: The CO₂ system has excellent waste heat recovery capability, which can recycle the waste heat from refrigeration to store heating and domestic hot water supply, realizing multi-purpose use of one system, and significantly reducing the store’s comprehensive energy consumption and operating costs.
When CO₂ May Not Be the Best Option
Some special types of supermarket stores are not suitable for blindly landing CO₂ refrigeration renovation, rash upgrading will be a mismatch between investment and revenue, the overall cost-effectiveness is extremely low.
Small independent supermarkets with limited budgets can hardly afford the high initial investment in CO₂ high-pressure equipment and professional installation, and can not dilute the cost through large-scale operation;
Stores with short-term business planning, no long-term layout plans, can not enjoy the CO₂ system of long-term energy saving, free of compliance rectification of the dividends of the investment payback cycle is seriously imbalanced; remote, no professional technical operation and maintenance support stores, easy to equipment failure can not be timely maintenance, daily maintenance is not in place and other issues, affecting the stability of the system, and an additional increase in the operation of hidden dangers;
Stores located in extreme high-temperature areas and not equipped with energy-saving optimization equipment such as injectors and adiabatic cooling have high energy consumption for CO₂ system operation, and are unable to take advantage of energy saving. In view of the above scenarios, stores can suspend the full-scale transformation, prioritize the use of traditional low-carbon hybrid refrigeration solutions for a smooth transition, and then complete the upgrading and transformation when the conditions are ripe.
Key Decision Factors for Supermarkets
Supermarkets in the selection of CO₂ refrigeration system, need to be combined with the six core dimensions of comprehensive research and judgment, abandon blind investment, matching the store’s operating status quo and long-term development planning, the specific assessment of factors categorized as follows:
- Regional climate: warm and cold climate areas can give full play to the CO₂ system energy efficient, stable operation of the core advantages; high temperature and hot areas need to be matched with energy-saving accessories to make up for the shortcomings of the efficiency of high-temperature working conditions.
- Store operating scale: large supermarket chains can rely on large-scale procurement and standardized operation and maintenance to dilute the input cost, the overall investment is more cost-effective; small single supermarket capital pressure, difficult to dilute the cost of the selection of the type of prudent assessment.
- Project construction type: new stores can be tailored to fit the high-pressure refrigeration system, strong adaptability, low difficulty in landing; the old store renovation process is cumbersome, high transformation costs, and construction is easy to affect the normal business of the store.
- Budget and return cycle: long-term operation of the store can fully enjoy the long-term dividends of energy saving and compliance; limited budget, short-term operation of the store back to the capital cycle is longer, the overall cost-effective investment is relatively insufficient.
- Strength of local environmental protection policies: in areas with strict HFC control, CO₂ refrigeration is the optimal solution to avoid environmental fines, equipment elimination and asset stranding; relaxed policy areas can combine their own business rhythm, and flexibly adjust the transition progress.
- Technical conditions for future operation and maintenance: the surrounding professional operation and maintenance team can effectively reduce the probability of equipment failure and maintenance costs; remote, technically weak areas are prone to maintenance is not timely, unstable operation of the equipment and other issues, increasing the operation of hidden dangers.
Conclusion
Carbon dioxide refrigeration by virtue of environmental protection, compliance, safety, high energy-efficiency core advantages, to become a super alternative to the inevitable trend of traditional refrigeration. Although the initial investment and transformation threshold is high, but the technology upgrades continue to improve its cost-effectiveness, is a super compliance, long-term energy saving and cost reduction of the preferred program.
High-quality control system is the key to the efficient operation of carbon dioxide refrigeration. Relying on intelligent controllers, valves, sensing devices and Internet of Things monitoring, it can effectively stabilize equipment, reduce energy consumption and realize intelligent operation and maintenance.
CORESTAR focuses on HVACR control solutions, mainly engaged in all kinds of refrigeration control, sensing and IoT communication products, support OEM/ODM customization, can provide energy-efficient refrigeration system integration solutions.
