Refrigeration
CO₂ Refrigeration
CO₂ refrigeration has become the standard for new commercial refrigeration installations across Europe and is increasingly adopted in industrial cold storage, food processing and combined cooling and heating applications. Its zero ozone depletion potential, global warming potential of 1 and strong thermodynamic performance make it one of the most important refrigerants in the transition to natural refrigerant systems.
NEXT Lubricants supports CO₂ refrigeration with compressor lubricants developed for transcritical, subcritical and cascade system configurations.
Compression process
CO₂ Refrigeration — Process, Applications & Compressor Role
Carbon dioxide (CO₂) is one of the fastest-growing natural refrigerants in both industrial and commercial refrigeration — valued for its zero ozone depletion potential, global warming potential of 1 and strong thermodynamic performance across a wide operating range. CO₂ operates at significantly higher pressures than conventional refrigerants — typically between 35 and 130 bar depending on system configuration — and its behaviour around and above the critical point (31.1°C / 73.8 bar) creates operating conditions that differ fundamentally from other refrigeration applications.
The compressor in a CO₂ system must handle these significantly higher operating pressures across both subcritical and transcritical conditions. In transcritical operation — where CO₂ passes through a gas cooler above its critical point rather than condensing conventionally — the compressor discharge pressure is determined by gas cooler conditions and system control strategy rather than refrigerant condensing temperature, meaning operating conditions can vary considerably across seasons and load profiles. This makes CO₂ one of the more technically demanding refrigerants from a compression and lubrication standpoint.
Supermarket & Food Retail Refrigeration
Transcritical CO₂ booster systems are the dominant refrigeration technology in new supermarket installations across Europe, handling both medium-temperature display cases and low-temperature freezer duties in a single integrated circuit.
Industrial Cold Storage & Food Processing
CO₂ handles the low-temperature stage in cascade systems at large industrial cold stores, freezing tunnels and food processing plants, operating in subcritical mode against an ammonia or secondary refrigerant high stage.
Ice Rinks & Sport Facilities
Direct CO₂ refrigeration is used in ice rink applications where environmental performance and the ability to use CO₂ as the primary refrigerant throughout the circuit makes it a strong choice for new and retrofit installations.
Combined Cooling & Heating
Transcritical systems are increasingly specified where heat recovery from the gas cooler is integrated into building heating, hot water or process heating — making productive use of the elevated temperatures available at the high side.
Related Applications
Explore Other Refrigeration Applications
CO₂ refrigeration is one part of a broader refrigeration landscape. NEXT Lubricants also supports the following natural refrigerant applications.
Ammonia Refrigeration
Large-scale industrial refrigeration using R717 across cold storage, food processing and industrial cooling applications.
Hydrocarbon Refrigeration
Refrigeration applications using hydrocarbon refrigerants where system design and operating conditions can differ from ammonia-based systems.
Industrial Heat Pumps
Applications where heat is recovered and upgraded for industrial use, often with different system conditions and operating profiles.
HFC & HFO Refrigeration
Refrigeration systems using HFC or HFO refrigerants, with different system and lubricant requirements from natural refrigerant applications.