R32

Chemical Properties and Characteristics of R32

R32 (difluoromethane) is an organic fluorine compound represented by the chemical formula CH2F2 and belongs to the group of HFCs (hydrofluorocarbons) as a single-component refrigerant. Due to its low boiling point and excellent thermal conductivity, R32 is suitable for refrigeration and air conditioning equipment such as air conditioners. The characteristics of R32 include the following points:

Low Boiling Point

With a low boiling point of -51.7°C, efficient heat exchange is possible.

High Thermal Conductivity

Compared to conventional refrigerants, it has higher thermal conductivity, contributing to improved energy efficiency.

Low Viscosity

Due to its high fluidity, there is less pressure loss within the piping, enhancing the overall system efficiency.

Additionally, since R32 is a single-component refrigerant, even if leakage occurs, its composition does not change, making it easy to replenish and recover.

Comparison of R32 with R410A and R22

Compared to conventional refrigerants such as R410A and R22, which have been widely used, R32 excels in terms of environmental performance and energy efficiency. The specific points of comparison are as follows.

The GWP value of R32 is 675, which is less than one-third of that of R410A or R22, significantly reducing its impact on global warming. However, a GWP of 675 indicates that it has 675 times the greenhouse effect of carbon dioxide. While the GWP of R32 is significantly lower than conventional refrigerants, further improvement is still needed. Additionally, since its ozone depletion potential (ODP) is 0, it can be considered an excellent refrigerant from the perspective of ozone layer protection.

Next, let's look at it from the perspective of energy consumption efficiency. R32 refrigerant is known for its excellent energy efficiency. For example, compared to conventional refrigerants such as R22 and R410A, it has approximately 1.5 times the cooling capacity. This high cooling capacity allows for a reduction in the amount of energy required to achieve the same cooling effect, thereby contributing to the compactness of equipment and resource conservation.

From the perspective of the Cooling Seasonal Performance Factor (CSPF), R32 also demonstrates superior performance compared to conventional refrigerants. CSPF is an indicator that represents the efficiency of an air conditioner over the course of a year, and equipment using R32 achieves high CSPF values.

Safety of R32 Refrigerant

R32 refrigerant is classified as a mildly flammable refrigerant (A2L) under the international standard ISO 817:2014. This classification represents the lowest flammability category and has the following characteristics:

Characteristics of Mildly Flammable Refrigerants (A2L)

Burning VelocitySlow, at 10 cm/s or less

Flame PropagationNo horizontal propagation

Explosive CombustionUnlikely to occur

As such, the heat of combustion for R32 is 9 MJ/kg, which is relatively low compared to other flammable refrigerants, and the impact range during combustion is limited. However, to ensure safety, strict risk assessments are conducted during the design and manufacturing of equipment.
Specific safety measures include the introduction of refrigerant leak detection systems, the installation of appropriate ventilation equipment, and safety education for workers. These measures help minimize the risks associated with the use of R32 refrigerant.

Challenges Related to the Use of R32

Further Reduction of GWP Value

International agreements mandate the phased reduction in the use of HFC refrigerants, including R32, by around 2030.

Obligation to Reduce Usage

International agreements mandate the phased reduction in the use of HFC refrigerants, including R32, by around 2030.

Ensuring Safety

As a mildly flammable refrigerant, careful handling is required.

To address these challenges, efforts are being made to accelerate research and development of low-GWP refrigerants, explore alternative refrigerants, and innovate technologies to enhance safety. Additionally, establishing systems for the recovery and reuse of R32 is also an important initiative.