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CO2 solutions

One refrigerant, four alternatives


Standard CO2 solution

The European Community is committed to reducing greenhouse gas emissions into the atmosphere. Since CO2 has a GWP of 1, it is clear that systems that use natural CO2 refrigerant are the best possible choice for ensuring an extended useful life.

Every component in Arneg systems is designed to withstand the increase in pressure caused by even extended idle periods.

A green choice
Suitable for all climatic conditions
Extended system life guaranteed
Operating costs constant over time
No need for F-gas declarations

CO2 solution with parallel compressor

The use of a CO2 refrigeration system with a parallel compressor gives you around 7-10% higher efficiency and lower consumption than you could achieve from a standard system.

This solution achieves maximum efficiency during the summer months, when a large amount of vapour is generated in the refrigeration circuit.

Greater energy efficiency
7-10% lower consumption than standard systems

CO2 solution with parallel compressor and ejector

The ejector is a component that transforms the high pressure differential between the gas cooler and the liquid receiver into useful work. It replaces the back pressure valve. It aspirates gas from the NT line at 27 bar and delivers it to the parallel compressor at 34 bar, at a 7 bar pressure increase.

This solution exploits the energy and pressure differential generated within the system to produce cost-free pressure increases that help reduce consumption.

Further optimisation of energy performance
10-15% lower consumption than standard systems

CO2 solution with adiabatic post-cooler

A CO2 refrigeration system with an adiabatic post-cooler is an alternative solution to a system with an ejector. It uses the latent heat of evaporation to reduce system consumption. By increasing the humidity of the air, the post-cooler can reduce its temperature by at least 8°C. For example, if outdoor temperature is 35°C, the post-cooler will enable the CO2 refrigeration system to work at 27°C.

This technology is particularly suited to hot climates and to the hot summer months in general. In the absence of water, you can use a chiller instead of the adiabatic post-cooler to cool the CO2 leaving the gas cooler.

Greater energy efficiency even in hot areas
15% reduction in consumption, especially in the summer


Recupero calore per acqua calda sanitaria

+ Heat recovery for domestic hot water

This solution allows you to use the high temperature of the refrigerant (70-100°C) at the end of the refrigeration cycle to produce domestic hot water.

This solution eliminates the need to use gas or electrical energy to produce domestic hot water, leading to significantly lower energy consumption.

Recupero calore per riscaldamento

+ Heat recovery for heating

This solution uses the high temperature of the refrigerant at the end of the cycle to heat your store.

This reduces the need for gas or electrical energy to power heating systems, leading to significantly lower energy consumption.

Produzione di acqua fredda per raffrescamento

+ Cold water production for cooling

Our transcritical CO2 system can also produce cold water for cooling your store and offices.



For a complete solution, you can integrate all the accessories described above into an HVAC system. At Arneg, we offer a range of technological solutions to satisfy all your needs.

With this solution, you obtain a complete climate control system, in which a single food refrigeration plant satisfies all your food display refrigeration and building air conditioning requirements.