Refrigerant R404a: properties, features, applications

In the article we will consider the characteristics of the R404a refrigerant (freeon R-404a). Let’s talk about its features, give tables of characteristics and dependences of boiling pressure on temperature. We will also give compatibility with oils and safety precautions for handling refrigerant. If you plan to transfer equipment to another refrigerant, we recommend that you read the publication about R404a freon analogues.

History of appearance and application

The R404a refrigerant was developed as an alternative to R502 and R22 freons. Since 1993, it has been used to fill new refrigeration equipment. After it began to be used for retrofit systems on R502 and R22. In this case, it is necessary to replace mineral oil with synthetic and a filter-drier.

The need to replace freons R502 and R22 is associated with their ban by the Montreal Protocol due to their high ozone depleting potential. In the future, the r404a refrigerant may also be banned due to the high global warming potential. But at the moment it is widely used because of the good technical characteristics of r404a freon.

Freon is used in domestic and commercial refrigeration and freezing systems. It is used in low-temperature and medium-temperature equipment. Trademarks of freon R-404a:

• SUVA HP62;
• FX70;
• Genetron 404a;
• Forane 404a;
• Solkane 404a;
• HFC-404A;
• HFC-404;
• Freon 404a.

Features of freon R404a

Compared to R502, R404a has 4-5% better cooling performance. The discharge temperature is lower by 8%. Its Global Warming Potential (GWP) is 15.6% lower (4657 and 3922 respectively). The ozone depletion potential of HFC-404A is 0.

R404a freon is three-component. It consists of:

1. R-125 (44%);
2. R-143a (52%);
3. R-134a (4%).

Although the refrigerant contains flammable R-143a, R-404a itself is not flammable. But when mixed with air, it can ignite from an open flame or high temperature heat source.

Due to the fact that it is in pressurized cylinders, they cannot be subjected to heat. When heated to high temperatures, it releases toxic halogen compounds. Under normal conditions, the gas is not dangerous to humans. It has a safety class A1.

Freon-404a is a pseudo-azeotropic mixture. Its temperature glide is less than 0.5°C. Therefore, with a small leak, it can be refueled. But refueling must be done in the liquid phase. When adding refrigerant in the gaseous phase, there is a risk of getting the wrong ratio of components.

Specifications R404a

R404a pressure versus temperature

The table shows the dependence of pressure on temperature. Indicated absolute in bar. In order to get the gauge (gauge) pressure, it is necessary to subtract one from the value.

Oil compatibility

R404a refrigerant can only be used with synthetic polyol ester compressor oils. Their most common brands are:

• Suniso SL;
• Mobil Eal Arctic;
• Mobil Gargoyle;
• Esterol POE;
• Bitzer BSE;
• Shell clavus.

Safety

R404a gas components are heavier than air. When leaking, they accumulate in the lower part of the room. If a large leak occurs, the R404a freon will force out the air. This can be dangerous for people in small spaces and/or without ventilation.

Freon can cause frostbite if it comes into contact with skin or eyes. Damaged areas should be washed with warm water. In case of contact with eyes, rinse them for 15 minutes. After that, be sure to call for emergency help.

Short-term inhalation of gas does not cause negative effects. With long-term exposure, it replaces air in the lungs. This may lead to:

• disorientation and loss of coordination;
• clouding or loss of consciousness;
• Narcotic or anesthetic effect;
• suffocation;
• Violation of the heart rhythm; of death.

A person who has inhaled refrigerant vapors must be moved to fresh air. If the condition does not normalize, there are respiratory disorders, forced ventilation of the lungs is necessary. Before the arrival of doctors, it is necessary to carry out resuscitation measures – mouth-to-mouth breathing.

In this publication, we examined the characteristics of R404a freon. we hope it was useful to you. Don’t forget to share this article with your colleagues !