Next Gen Refrigerants: Why CO2 Is Rising in UK Cooling

The UK cooling and refrigeration sector is undergoing rapid transformation as businesses move away from high global warming potential refrigerants. At the centre of this shift is CO2. Once considered a specialist option, CO2 refrigeration systems are now widely recognised as the next generation of low carbon cooling technology. Driven by regulatory change, energy performance demands and sustainability targets, CO2 is becoming the preferred choice across supermarkets, hospitality, food production, healthcare and commercial buildings.

This article explains why CO2 is taking the lead in the UK, how the technology works and what businesses should consider when upgrading their systems. It also highlights how Green Cooling supports organisations seeking long term, energy efficient and environmentally responsible solutions.

Understanding CO2 as a Natural Refrigerant

• CO2, also known as R744, is a natural refrigerant with an extremely low global warming potential and zero ozone depletion potential.
• Unlike HFCs, which are synthetic, CO2 occurs naturally and does not contribute to long term atmospheric damage.
• Alongside ammonia and hydrocarbons, CO2 is part of a global movement towards natural refrigerants that reduce environmental impact and regulatory risk.
• The thermodynamic behaviour of CO2 provides advantages in modern systems.
• High heat transfer efficiency, fast pull down rates and strong performance in both heating and cooling applications make it suitable for a wide range of commercial requirements.

The UK Regulatory Landscape Driving CO2 Adoption

The UK’s F-Gas regulations strongly push the shift to CO₂ by phasing down high-GWP refrigerants. As quotas tighten, legacy gases like R404A and R507 become more restricted, expensive, and harder to source, while older systems face service bans, charge limits, and rising compliance demands.

Businesses must also manage stricter leak checks, detailed record-keeping, and penalties for non-compliance. Sticking with synthetic refrigerants brings long-term risks, including higher service costs and vulnerability to future regulatory changes.

CO₂ (R744) avoids these issues. Its ultra-low GWP exempts it from the phasedown, offering stable supply, predictable costs, and simpler compliance. With growing sustainability requirements, CO₂ provides a future-proof refrigerant aligned with the UK’s environmental direction.

How Modern CO2 Refrigeration Systems Work

Transcritical CO2 systems

Commonly used in supermarkets, food production and large commercial spaces, transcritical systems operate above the critical point of CO2. These systems deliver high performance even under varying temperatures. They are particularly effective in the UK climate, where moderate ambient temperatures allow them to run with excellent energy efficiency throughout the year. Modern transcritical systems incorporate technologies such as parallel compression, ejectors and gas coolers to improve performance during warmer periods. These features help commercial sites maintain stable temperatures, reduce energy consumption and achieve reliable operation even under heavy load.

Subcritical and cascade systems

These are often used in industrial environments where low temperature applications are required. They combine CO2 with another refrigerant in a secondary circuit to achieve extremely low temperatures with strong efficiency. Cascade systems are ideal for environments such as food processing, cold rooms and manufacturing where temperatures below freezing are essential. The combination of CO2 on the low stage and another refrigerant on the high stage reduces pressure demand, improves stability and allows systems to achieve precise temperature control. This configuration also provides design flexibility, enabling businesses to meet specific cooling requirements without compromising energy efficiency.

Booster systems

Booster designs use CO2 across both medium and low temperature circuits. This creates a simplified structure with reduced maintenance requirements and improved energy performance. Using a single refrigerant throughout the system minimises complexity, reduces the number of components and streamlines servicing. Booster systems are well suited to supermarkets, retail environments and mixed load applications where multiple temperature zones are required. They offer consistent performance, strong reliability and excellent efficiency, particularly when combined with heat recovery or smart control strategies.

Energy and Performance Benefits of CO2 Systems

Energy efficiency

Modern CO2 systems use intelligent controls, variable speed compressors and high efficiency components to deliver significant energy savings. For sites operating around the clock, even small efficiency gains result in major long term reductions in operational costs.

• Advanced optimisation algorithms continually adjust system performance to match real time demand, ensuring energy is only used when necessary.

Heat recovery opportunities

CO2 refrigeration systems allow businesses to reclaim waste heat from the cooling process. This heat can be repurposed for hot water, heating or pre heating services, reducing energy consumption and carbon emissions.

• Integrated heat recovery modules can supply a consistent source of renewable heat, helping businesses cut reliance on traditional boilers and lower overall energy bills.

Lifecycle value

Although installation costs can be higher than traditional systems, CO2 technology delivers strong return on investment through energy savings, lower refrigerant costs and reduced compliance expenditure. With HFC price volatility expected to continue, CO2 offers long term financial stability.

Safety and reliability

CO2 is non flammable and non toxic in typical operational conditions. With the correct system design and safety measures, it offers excellent reliability. Pressure management, leak detection and robust engineering play a vital role in ensuring safe operation.

• Modern monitoring systems provide continuous performance tracking, enabling early detection of irregularities and ensuring safe, stable operation at all times.

Applications Across UK Industries

Supermarkets and retail: CO2 is the leading choice for chilled and frozen food environments where efficiency, temperature control and compliance are essential.

Food production and manufacturing: Production facilities rely on reliable cooling with minimal downtime. CO2 systems provide consistent performance across demanding conditions.

Hospitality and leisure: Hotels, restaurants and entertainment venues benefit from the energy efficiency and heat recovery opportunities that CO2 offers.

Healthcare and public sector: Precise temperature control and dependable performance make CO2 suitable for laboratories, hospitals and pharmaceutical environments.

Industrial and large scale cooling: From distribution hubs to cold chain logistics, CO2 offers the power and reliability required for continuous operation.

Technical Challenges and How They Are Overcome

Like any advanced technology, CO2 systems require specialist expertise. High pressure operation demands accurate system design, precise commissioning and ongoing optimisation. Skilled engineers ensure correct pipework sizing, valve selection, safety strategies and control logic.

Innovations continue to reduce barriers. Modern CO2 equipment features improved pressure management, optimised heat exchangers and advanced diagnostics. New sensor technologies and machine learning tools are emerging to support predictive maintenance and rapid fault detection.

With correct engineering and regular maintenance, CO2 systems deliver high performance, reliability and long service life.

Future Innovations and the Outlook for CO2 in the UK

CO2 is no longer an emerging option. It is firmly established as the leading next generation refrigerant in commercial and industrial applications. Its rapid rise is driven by strong regulatory alignment, proven energy performance and long term stability compared with high GWP synthetic refrigerants. As more UK organisations prioritise carbon reduction and lifecycle efficiency, CO2 continues to outperform alternative low GWP options in both reliability and operational sustainability.

• CO2 heat pump development
  Ongoing advancements in CO2 heat pump technology are enabling higher system capacities, improved hot water production and better year round performance. These developments create new opportunities for buildings seeking integrated heating and cooling solutions with lower carbon output.
• Enhanced energy recovery systems
  Next generation CO2 systems feature more efficient heat reclaim options, allowing businesses to capture and reuse a greater proportion of waste heat. This supports lower operating costs and helps organisations meet decarbonisation targets.
• Smarter control integration
  Intelligent control systems are becoming more advanced, using optimisation algorithms, predictive analytics and real time monitoring to ensure systems operate at peak efficiency. This reduces energy use, improves reliability and extends equipment life.
• Efficiency improvements for high ambient conditions
  Engineering innovations focused on warm weather performance, such as ejectors, adiabatic systems and improved gas cooler designs, continue to expand the suitability of CO2 for a wider range of climates and applications.

Why Green Cooling Leads the Way in CO2 Refrigeration

Green Cooling has over two decades of experience delivering bespoke, sustainable and energy efficient cooling solutions. As specialists in natural refrigerants, we design, install and maintain CO2 refrigeration systems tailored to the exact needs of each client. Our engineering team has extensive experience with transcritical and subcritical system design, heat recovery integration and long term performance optimisation.

Our partnership network, including innovators in natural refrigerant technology, allows us to provide market leading solutions for businesses seeking reliable and environmentally responsible systems.

From supermarkets and stadia to food production and hospitality, we work closely with clients to deliver systems that support sustainability goals while reducing energy consumption and operating costs.

Final Takeaway

CO2 refrigeration systems represent the future of cooling in the UK. With strong efficiency, excellent environmental performance and full regulatory compliance, CO2 is a compelling solution for any business planning its next refrigeration investment. As the UK continues its transition to low carbon technologies, CO2 offers a reliable, future proof and cost effective approach to commercial cooling.

To explore how CO2 refrigeration systems could benefit your organisation, contact the Green Cooling team today. Our experts can guide you through system design, feasibility, installation and long term maintenance to ensure the best performance from your cooling infrastructure.