Is R290 Refrigerant Really Unsafe?

It is a well-known common sense that the air-conditioning refrigerant Freon has the effect of destroying the atmospheric ozone layer and aggravating the greenhouse effect. At a time when the global warming situation is becoming more and more serious, the use and promotion of more environmentally friendly refrigerants have become the focus of the home appliance industry. Following the R22, R410A and R32 refrigerants, a new refrigerant called R290 have recently entered the public eye.

The Kigali Amendment clearly lists 18 hydrofluorocarbons (HFCs), including HFC134, HFC134a, HFC143, and HFC245fa, on the list of controlled substances. HFC-410A (R410A refrigerant) and HFC-32 (R32 refrigerant) commonly used in air conditioners are both under the control of this amendment.

In the future when HFCs face the fate of control and elimination, the top priority of the home appliance industry is to seek more environmentally friendly alternatives. The R290 refrigerant, as the only refrigerant that can meet the requirements of the amendment among the existing alternative products, has attracted the attention of the home appliance industry.

In everyone’s common sense, Freon is a substance that can break the ozone layer. In fact, Freon is a general term for a class of substances. It can be roughly divided into three categories, including chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons. (HCFC), hydrofluorocarbons (HFC). Among those that destroy the atmospheric ozone layer are chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs), which contain chlorine, which catalyzes the conversion of ozone to oxygen. Chlorofluorocarbons (CFCs) have been phased out due to their great damage to the ozone. Hydrochlorofluorocarbons (HCFCs) are much less damaging to ozone. Taking the most well-known refrigerant R22 among hydrochlorofluorocarbons (HCFCs) as an example, its ozone depletion potential value (ODP) is 0.05, which is the hydrogen percent of chlorofluorocarbons (HCFCs).

R290 refrigerant does not belong to Freon, its chemical name is propane, its ozone layer destruction potential value (ODP) is 0, and its global warming coefficient value (GWP) is only 3.3. In addition to being environmentally friendly enough, R290 refrigerant also has high thermal conductivity. , the advantages of larger latent heat of evaporation, small molecular weight, good fluidity, lower delivery pressure, and small compressor load, the use of R290 refrigerant can prolong the service life of the compressor, and the refrigerant charge can be compared with traditional refrigerants. Save 30%.

From the perspective of environmental protection and performance, R290 is indeed the most suitable alternative at present, but it is difficult to promote it on a large scale. Why do you say that? The reason is that propane is a flammable and explosive substance, and the liquefied natural gas we use contains propane.

The flammability of R290 is A3, which is a flammable substance. However, the safety of R290 has been questioned, and explosion accidents have occurred frequently. The flammability of the R32 refrigerant that consumers are concerned about is A2, which is a flammable substance. That is to say, it is difficult to promote the R32 refrigerant with a lower flammable level and more severe combustion conditions, let alone the R290 refrigerant which is a flammable and explosive substance.

In fact, there is no need to be so pessimistic. First of all, R290 can explode only when the concentration is between 2.1% and 9.5%, and the ignition temperature of 470°C is reached at the same time. Above or below this concentration, it will not explode!

Secondly, although R290 refrigerant is flammable, it does not mean that air conditioners using R290 refrigerant have potential safety hazards. The reason why R32 air conditioners often explode is not that the safety of the air conditioners is not up to standard, but the real culprit is the refrigerant leakage caused by improper installation.

For example, during the installation, the site must be ventilated, and the explosion has no heat source and open flame. When it is necessary to lengthen the air-conditioning copper pipe to ream the copper pipe, a special reaming instrument is required to ensure the integrity of the copper pipe. After the installation is completed, the air conditioner needs to be strictly tested for refrigerant leakage. As long as the operating specifications during installation and maintenance can be strictly guaranteed, the safety of R32 air conditioners is also very high.

Returning to the R290 air conditioner, the current research shows that the safety of the R290 air conditioner is trustworthy as long as the design and production are strictly implemented in accordance with safety standards, and the user’s operation is standardized.