CO₂ as a refrigeration system

Today, the refrigeration and air conditioning industry is undergoing a major transformation. Growing concern about the environmental impact of traditional refrigerants and new international regulations have driven the adoption of more sustainable technologies. In this context, CO₂ as a cooling system has become one of the most efficient, safe, and environmentally friendly solutions.

At Inditer, we constantly work to offer refrigeration solutions tailored to the needs of each industrial sector. Thanks to our experience in thermal engineering and our specialization in CO₂-based systems, we can design and implement high-performance equipment that combines energy efficiency, sustainability, and operational reliability.

Throughout this article, we will analyze in depth what CO₂ as a refrigerant is, how it works within cooling systems, what advantages it offers compared to other gases, and why it is becoming the benchmark standard in industrial and commercial refrigeration.

What is CO₂ as a cooling system?

Carbon dioxide (CO₂), known in refrigeration as R744, is a natural refrigerant used to transfer heat within a cooling system. Although its use in refrigeration is not new — it was already used at the end of the 19th century — in recent decades it has regained prominence due to its low environmental impact and high energy efficiency.

Unlike other synthetic refrigerants, CO₂ is a natural substance present in the atmosphere. This means that its use in refrigeration systems does not significantly contribute to global warming or the depletion of the ozone layer, making it an ideal alternative to traditional fluorinated gases.

CO₂-based cooling systems operate through a thermodynamic cycle similar to that of other refrigerants. The gas circulates through the system absorbing heat in the evaporator and subsequently releasing it in the condenser or gas cooler.

Within these installations, components specifically designed for CO₂ are essential to guarantee system performance and safety. For example, in our industrial solutions we integrate equipment such as the Gas Cooler, designed to optimize heat dissipation in transcritical CO₂ systems.

How does a CO₂ cooling system work?

To understand how CO₂ cooling systems operate, it is necessary to understand the refrigeration cycle that allows heat to be transferred from the space or product we want to cool to the outside environment.

The CO₂ refrigeration cycle

The process is based on four main stages:

1. Compression The CO₂ refrigerant is compressed by the compressor, increasing its pressure and temperature.
2. Heat rejection The hot gas passes through the heat exchanger, where it releases thermal energy to the environment. In transcritical systems, a gas cooler is used, which cools the gas without necessarily condensing it.
3. Expansion After cooling, the refrigerant passes through an expansion valve that reduces its pressure and temperature.
4. Evaporation The cold CO₂ enters the evaporator, where it absorbs heat from the environment that needs to be cooled.

In this final stage, evaporators specifically designed for CO₂ play a key role in achieving maximum thermal efficiency. At Inditer, we develop specialized solutions such as CO₂ Evaporators, optimized to deliver effective heat exchange even in demanding industrial applications.

Subcritical and transcritical systems

CO₂ cooling systems can mainly be classified into two types:

• Subcritical systems
  They operate at pressures and temperatures where CO₂ behaves similarly to other traditional refrigerants.
• Transcritical systems
  They operate above the critical point of CO₂. In this case, the refrigerant does not condense in the conventional way and a gas cooler is used to dissipate the heat.

Today, transcritical systems are the most widely used, especially in large commercial and industrial installations.

Advantages of CO₂ compared to other refrigerants

The growing use of CO₂ in cooling systems is not accidental. This natural refrigerant offers multiple benefits that position it as one of the best alternatives for the future of refrigeration.

Minimal environmental impact

One of the main reasons for adopting CO₂ is its low Global Warming Potential (GWP).

While many fluorinated refrigerants have GWP values above 1000, CO₂ has a GWP of 1, meaning its climate impact is extremely low.

In addition, it does not affect the ozone layer, unlike other gases historically used in refrigeration.

High energy efficiency

CO₂-based cooling systems can achieve very high efficiency levels, especially when properly designed and optimized for each application.

This translates into:

• Lower energy consumption
• Reduced operating costs
• Higher thermal performance

At Inditer, we optimize each system through the design of specific heat exchangers, ensuring maximum energy efficiency from CO₂.

Safety and availability

CO₂ is a non-flammable and chemically stable refrigerant, making it a safe option for industrial and commercial applications.

In addition:

• It is abundant in nature
• It is not subject to production restrictions
• Its cost is relatively low

This makes it a sustainable refrigerant from both environmental and economic perspectives.

Industrial applications of CO₂ in cooling systems

The use of CO₂ has rapidly expanded across numerous sectors due to its technical and environmental advantages.

Commercial refrigeration

One of the sectors where CO₂ has experienced the greatest growth is commercial refrigeration, especially in supermarkets and logistics centers.

Large retail chains have adopted transcritical CO₂ systems for:

• cold storage rooms
• refrigerated display cabinets
• food storage

Food industry

The food industry requires extremely reliable cooling systems to ensure product preservation.

CO₂ allows stable and efficient temperatures to be maintained in processes such as:

• industrial freezing
• refrigerated storage
• food processing operations

Pharmaceutical and logistics industry

Pharmaceutical and cold-chain logistics applications also benefit from CO₂ due to its thermal precision and operational reliability.

Cooling systems based on this refrigerant allow precise control of the temperature conditions required for the transport and storage of medicines and healthcare products.