R404A Refrigerant - Phasing Out and Replacement
R404A refrigerant is a commonly used refrigerant in low and medium-temperature refrigeration applications However, due to its high Global Warming Potential (GWP), it is being phased out and replaced with refrigerants that have a lower GWP This article aims to provide an understanding of the phasing out of R404A refrigerant and its replacement options
The Function of R404A Refrigerant
R404A refrigerant plays a crucial role in low and medium-temperature refrigeration applications by absorbing heat from the environment and transferring it to the condenser, where it is released into the atmosphere This refrigerant is a blend of HFC refrigerants R125, R143a, and R134a, each contributing to the refrigerant's thermodynamic properties, such as boiling point, critical temperature, and pressure. Consequently, R404A is suitable for use in a wide range of commercial refrigeration systems, including cold storage, supermarket refrigeration systems, and ice rinks.
The refrigeration process begins when R404A enters the evaporator, a heat exchanger in contact with the environment to be cooled As the refrigerant flows through the evaporator, it absorbs heat from the environment, causing it to evaporate and become a low-pressure gas The low-pressure gas flows to the compressor, where it is compressed and converted into a high-pressure gas The high-pressure gas then flows to the condenser, another heat exchanger in contact with the atmosphere, where it releases heat into the atmosphere, causing it to condense back into a liquid The liquid refrigerant then flows through an expansion valve, reducing its pressure and temperature, and the cycle starts again
Phasing Out R404A Refrigerant
The phasing out of R404A refrigerant is in response to increasing concerns about climate change and its impact on the environment The EU F-gas Regulation, No 517/2014, aims to reduce emissions of fluorinated gases, including hydrofluorocarbons (HFCs) that have a high GWP The regulation prohibits the construction of fixed refrigeration units that use refrigerants with a GWP of over 2500 As a result, new R404A plants are no longer permitted as of the beginning of 2020
Replacement Options for R404A Refrigerant
Alternative refrigerants for R404A include natural refrigerants such as ammonia (NH3) and carbon dioxide (CO2), which have a GWP of zero New replacement refrigerants such as R1234yf and R1234ze also have a lower GWP of less than 10 The choice of replacement refrigerant depends on the system and purpose of use For example, ammonia is commonly used in large industrial refrigeration systems, while R1234yf is used in automotive air conditioning systems
Replacing R404A refrigerant with a lower GWP alternative may require modifications to the existing system. For example, ammonia is not compatible with certain materials used in some refrigeration systems, and carbon dioxide requires higher operating pressures than R404A. Therefore, it is important to consult with a qualified technician or refrigeration engineer before making any changes.