Subcritical refrigeration systems with R744 (CO₂) – a reliable and sustainable solution for industry

In the face of increasingly stringent environmental regulations and the need for energy efficiency, refrigeration systems with R744 (carbon dioxide – CO₂) are proving to be an excellent solution. Particularly popular are the so-called subcritical R744 systems , which are used in controlled environments where the operating pressure remains below the critical point of CO₂.

What are subcritical R744 systems?

The subcritical R744 system operates at pressures and temperatures that do not exceed the critical point of CO₂ (31.1°C and 73.8 bar). This allows condensation of the refrigerant and the use of a traditional thermodynamic cycle. The main components of these systems include:

• compressor designed to operate at high pressures;
• gas cooler or condenser (depending on conditions);
• expansion valve;
• evaporator adapted for CO₂.

Advantages of subcritical CO₂ systems

Environmental friendliness - R744 has GWP = 1 and ODP = 0 - does not damage the ozone layer and does not contribute to global warming.

High thermal conductivity – CO₂ has very good thermal efficiency, allowing for more compact heat exchangers.

Safety – carbon dioxide is non-toxic and non-flammable.

Low price and availability of the refrigerant – CO₂ is a natural substance and is not subject to quotas under the F-Gas regulations.

Applications of subcritical systems

Subcritical CO₂ systems are suitable for:

• industrial cold storage facilities;
• process cooling in the food industry;
• cooling installations in logistics and commercial facilities;
• marine ref