Refrigerant Sensor Solutions for Next-generation Refrigerant Gas Leak Detection

May 17,2023

Refrigerants refer to the medium substances used in heat engines to help realize energy conversion, and are widely used in household air conditioners, refrigerator freezers, car air conditioners and other fields.

From the perspective of the replacement process of refrigerants in the household air-conditioning industry:

The first generation is chlorofluorocarbons (CFCs), which have higher ODP and GWP values;

The second generation is hydrochlorofluorocarbons (HCFCs), and its ODP value is relatively lower than that of the first generation

The third generation is hydrofluorocarbons (HFCs), whose ODP value has reached 0, but the GWP value is still high;

The fourth generation is hydrofluoroolefins (HFOs), whose ODP and GWP values are very low, almost close to 0.


At present, there are four types of air-conditioning refrigerants that have been commercialized in the market:

Serial number ODP GWP Safety  Remark


0.05 1700  A1 Phased out



0 2100  A1 Replaces R22, but needs to be completely drained for maintenance
R32 0 675-771  A2 Replace R410, but the working pressure is higher, and the equipment needs to be modified
R290 0 20  A3 The working pressure is higher than R32, and it is more dangerous 


R32 refrigerant

R32, difluoromethane, molecular formula: CH2F2, is a new type of environmentally friendly refrigerant. It does not contain chlorine and has no destructive effect on ozone, but it is flammable and explosive. It is one of the substitutes of R22 and R410A refrigerants.

R32 refrigerant parameters
English full name: difluoromethane Chemical formula: CH2F2
Molecular weight: 52 Standard boiling point: -53℃
Critical temperature: 78°C Critical pressure: 5.8MPa (absolute pressure)
Critical density: 0.430g/cm3 CAS number: 75-10-5
Evaporation potential at boiling point: 390kJ/kg Specific heat (liquid, 25°C): 2.35kJ/kg.°C
Ozone Destruction Potential ODP: 0 Global warming coefficient GWP: 0.11


Since the GWP of R32 is still relatively high, the current GWP requirement for new-generation refrigerants in Europe is no higher than 150, which means that from 2025, R32 may be banned in many new EU air-conditioning equipment. 

Theoretically, promising refrigerants to replace R32 include the fourth-generation refrigerants R1234yf and R290 (propane).  

R290 refrigerant

R290 refrigerant, Chinese name refrigeration grade propane, chemical formula C3H8. R290 is a hydrocarbon refrigerant that does not damage the ozone layer at all, and has a very small greenhouse effect, making it one of the most environmentally friendly refrigerants.
However, R290 refrigerant is more flammable than R32, and its flammability has reached the A3 level.

R290 Refrigerant Parameters
English full name:propane Chemical formula: CH3CH2CH3, C3H8
Molecular weight: 44 Standard boiling point: -42.2℃
Critical temperature: 96.7℃ Critical pressure: 4.25MPa (absolute pressure)
Ozone Destruction Potential (ODP): 0 Global Warming Potential (GWP): 20


It is worth noting that the flammability and flammability of the new refrigerants R290 and R32 add a lot of risk factors to the installation and maintenance of the air conditioner. Once a leak occurs, it will lead to the paralysis of the refrigeration system, and it will cause suffocation, poisoning, pollution, and fire. Such accidents may even cause unimaginable consequences.

It is particularly important to find leakage faults accurately, quickly, scientifically and professionally and take corresponding safeguard measures in time. Weisheng Technology Refrigerant Gas Sensor  provides a solution for this. 

Recommended product model:

ZP211 refrigerant gas detection module
• Using advanced multi-layer thick film manufacturing process semiconductor gas sensor
• High sensitivity to R290 refrigerant gas
• Suitable for air conditioning, refrigeration system refrigerant leakage detection


ZP201 refrigerant gas detection module
• Detection of refrigerant gas R32
• PWM output
• Suitable for refrigerant leak detection in air-conditioning and refrigeration systems


ZRT510 Refrigerant detection module
• Detection of refrigerants using the principle of non-dispersive infrared (NDIR)
• Detection of R32, R454B refrigerant gas
• Suitable for HVAC equipment, industrial process and safety monitoring

MH-Z1542B-R32 Infrared Refrigerant Sensor
• A smart infrared gas sensor
• Use the principle of non-dispersive infrared (NDIR) to detect R32 and R454B refrigerants
• Suitable for HVAC equipment, industrial


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