The partner’s materials.
Frascold clarifies
The guide to CO2, the efficient and sustainable refrigerant
In the past years, interest in natural refrigerants has grown considerably, supported by the search for increasingly advanced solutions with less environmental impact. Frascold has created a guide for the use of natural refrigerants and the specific choice of the most suitable technology to guarantee maximum efficiency in different application areas. Let's take a look at the features and benefits of R744 refrigerant.
The role of CO2 in sustainable development and technological innovation
CO2, known in the HVAC&R world as R744, is the only natural refrigerant that is non-flammable, non-toxic at low concentrations, colourless and odourless. Due to its ODP of 0 and GWP of 1, it has excellent thermodynamic properties such as high volume cooling capacity and excellent heat exchange coefficient.
Compared to other natural refrigerants, carbon dioxide stands out for its high efficiency in subcritical applications. This allows the manufacturing of compact systems while maintaining the same cooling capacity, thanks to the better interaction between the coolant temperature and the auxiliary fluid temperature.
Subcritical and transcritical operation differs through the scope depending on the operating temperature and pressure. The subcritical operation takes place in the presence of low temperatures and moderate operating pressures, a common mechanism in applications such as commercial refrigeration. Transcritical operation is used in medium temperature applications such as heat pumps and heat recovery.
The high operating pressures and the low critical point of CO2 require more robust compressors that support higher stresses, in order to provide the same performance as traditional systems.
The compressor must overcome the challenges of CO2, i.e. higher pressures and discharge temperatures that lead the system to work in a transcritical regime, especially where air exchangers are used on the high pressure side.
To fully meet the thermodynamic characteristics of the R744 refrigerant and its challenges, it is necessary to optimise the reliability and efficiency of the heating and cooling systems with this refrigerant.
The main application of R744 is commercial refrigeration, but recently it is also growing in heat pumps. The refrigerant is an effective alternative to HFCs (hydrofluorocarbons) due to its high efficiency and incredible sustainability, and is increasingly used by retailers who need large refrigeration systems.
In addition to commercial refrigeration, R744 is used in heat pumps, with systems that enhance its ability to efficiently absorb and release heat, both for heating and cooling. This flexibility makes CO2 particularly suitable for commercial and industrial applications, especially with high Delta T water values.
Frascold offers two CO2solutions: the SK3 series for CO2 operation in subcritical applications and the new TK HD series for CO2 operation in transcritical applications.
The SK3 series consists of 15 models with evaporation temperatures from -50°C to -10°C and condensation temperatures up to 20°C, ensuring high energy savings and maximum sustainability. Designed for all sectors, including commercial, industrial and process cooling, it is suitable for single-stage, booster and cascade systems. The entire SK3 range is equipped with specific solutions to reduce delivery pulsations, which have proven to be very effective in multicompressor installations.
The new TK HD series for transcritical CO2 includes 4 sizes and 34 models and is designed to operate in harsh conditions. Thanks to Frascold's continuous innovation and field testing, the series is optimised to operate at high Delta P, high operating temperatures and guarantees continuous 24/7 operation, even under inverters. The sturdiness and reliability of the TK HD range make it ideal for heat pumps in industrial applications, with exceptional performance and superior life cycle. The series is distinguished by the use of highly resistant components, optimised lubrication and silent operation, with sound pressure levels at 1 metre distance ranging from 63.8 to 76 dB(A).
Frascold offers a unique advantage thanks to the expertise of our team and our proactivity, with a focus on quality and sustainability.