When using household appliances, users rarely think about what exactly makes food freeze and remain fresh. However, when a leak occurs or the compressor needs to be refilled, the question of what the gas in the refrigerator is called becomes critical. In everyday life, this substance is most often called freon, but the technically correct name is refrigerant. It is this gaseous agent that circulates through the closed circuit of the system, changing its state of aggregation and removing heat from the chambers.
Modern refrigeration units can operate on various types of substances, and their chemical composition directly affects the efficiency and environmental friendliness of the device. If you hear a hissing sound when defrosting or notice that the compressor is humming but not cooling, the circuit may have depressurized. Refrigerants can be safe for humans, but dangerous for the ozone layer, or vice versa - environmentally friendly, but flammable. Understanding exactly what substance is used in your model will help you correctly assess the risks and cost of repairs.
In this article we will look in detail at how different types of gases differ, why manufacturers are switching to new formulas, and what to do if the instructions indicate an incomprehensible code. Knowing the markings will allow you to more accurately formulate the problem when calling a technician and avoid imposing unnecessary services.
⚠️ Attention: Refilling the refrigerator yourself without professional equipment and skills is strictly prohibited. Incorrect pressure or mixing of different types of refrigerants can lead to a compressor explosion or fire.
Basic name and principle of operation
The gas that provides cooling is designated in technical documentation as refrigerant or refrigerant. It is a volatile substance with a low boiling point that easily changes from a liquid to a gaseous state and back. The cooling cycle is based on a physical law: when evaporating, a liquid absorbs heat from the environment, and when condensing, it releases it. In a refrigerator, this process occurs continuously as long as the unit is connected to the electrical network.
Historically, the most popular name was the trademark Freondeveloped by DuPont in the 1930s. Over time, this term became a common noun, just as any copier is called a “copier”. However, today, under the general name, dozens of different chemical compounds with different code designations are hidden. Boiling point these substances at atmospheric pressure are usually about minus 30 degrees Celsius, which is ideal for domestic needs.
The principle of operation is that the compressor compresses gaseous refrigerant, turning it into a hot liquid, which then cools in the condenser (the black grill at the back). Passing through the capillary tube and entering the evaporator inside the chambers, the substance expands sharply and boils, actively absorbing the heat of the products. After this, the gas returns to the compressor again, and the cycle repeats.
Why is the gas not consumed?
In a working refrigerator, the refrigerant is not consumed and does not require replacement during its entire service life. This is a closed system, and if the gas has gone somewhere, it means there has been a leak through a microcrack in the tube or poor-quality soldering.
Main types of refrigerants: from R12 to R600a
Over the decades of development of the refrigeration industry, gas formulas have changed for the sake of efficiency and environmental standards. To understand what gas is in your refrigerator, you need to know the basic markings, which are divided into several generations. Each new generation was created to solve the problems of the previous one, be it toxicity, impact on the ozone layer or flammability.
Chlorofluorocarbons (CFCs) were the first to be widely used, the most famous of which was R12. It was a reliable and safe gas for humans, but it turned out that it catastrophically destroys the Earth's ozone layer. In 1987, the Montreal Protocol banned its production. They were replaced by hydrochlorofluorocarbons (HCFCs), such as R22, which caused less harm, but were still subject to phasing out.
Modern refrigerators are most often filled with one of two types of substances: hydrofluorocarbons (HFCs), for example, R134a, or hydrocarbons, such as how R600a. The former do not burn, but have a high global warming potential. The latter are absolutely environmentally friendly, but require special safety measures during production and repair due to the risk of explosion.
Marking and technical characteristics
To identify the type of gas, a numbering system developed by the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) is used. The code always begins with the letter R (Refrigerant), followed by numbers. This marking is applied to a special plate located on the back wall of the refrigerator, inside the chamber or on the base.
Parsing the numbers in the code helps to understand the chemical structure of the substance. For example, in three-digit codes for fluorine-containing compounds, the last digit indicates the number of fluorine atoms, and the penultimate digit indicates the number of hydrogen atoms plus one. For hydrocarbons, such as isobutane (R600a), a separate 600 series is used. Knowledge of the exact markings is necessary for selecting compressor oil and proper evacuation of the system.
It is important to note that different types of gases require different pressures to operate. R134a works at higher pressure than R600a. If a system designed for one type is mistakenly pumped with another, the refrigerator will either not freeze or the compressor will fail due to overload. Therefore, craftsmen always check the passport data before starting work.
| Marking | Chemical name | Safety | Application |
|---|---|---|---|
| R12 | Dichlorodifluoromethane | Toxic when burned | Old models (before 2000) |
| R134a | 1,1,1,2-tetrafluoroethane | Does not burn, non-toxic | Modern refrigerators |
| R600a | Isobutane | Explosive | Economical models (Bosch, LG) |
| R407C | Mixture of gases | Does not burn | Industrial and powerful models |
Environmental friendliness and safety for humans
The issue of refrigerant safety has become especially acute in recent years. Consumers are rightly concerned about whether a gas leak will harm the health of their households. Most modern refrigerants, such as R134a, are inert and do not pose a direct threat to life upon short-term contact in small concentrations. However, in the confined space of a small room, a large leak can displace oxygen, leading to suffocation.
The situation with isobutane (R600a) is different. This substance is a natural gas similar to that used in household lighters. In concentrations from 1.3% to 8.5% in air it forms an explosive mixture. That is why there is always a warning sign in the form of a flame on the back wall of refrigerators with R600a. Manufacturers minimize risks by using the minimum required doses of gas and making electrical contacts hermetically sealed.
As for the environment, the transition to R600a is dictated not only by energy savings, but also by concern for the planet. This gas does not deplete the ozone layer and has zero global warming potential, unlike its synthetic predecessors. The leakage of R600a into the atmosphere is less harmful to the climate than the leakage of synthetic analogues, despite the risk of fire.
⚠️ Attention: If you smell gas in the kitchen near a running refrigerator, immediately ventilate the room and do not turn it on electrical appliances or open fire. Call a specialist to look for a leak.
How to find out what kind of gas is in your refrigerator
The easiest way to determine the type of refrigerant used is to find the technical sticker. Usually it is located on the back metal panel of the case, but in some models, especially built-in or designer ones, the information is hidden inside the refrigerator compartment on the side wall or on the door. Look for the line “Refrigerant” or “Refrigerant”, next to which there will be a code, for example, R600a 58g.
If the sticker is worn off or missing, you can use the model number of the refrigerator. By typing it into a search on the manufacturer's official website or into spare parts databases, you will receive a complete specification. Also, the type of gas is often indicated in the operating instructions in the “Technical Specifications” or “Transportation” sections.
It is impossible to visually determine the gas, but you can make an assumption based on the year of manufacture and brand. European manufacturers (Bosch, Siemens, Electrolux) switched en masse to isobutane back in the late 90s. American and some Asian brands have been using R134alonger. Old Soviet refrigerators (“Biryusa”, “Saratov”) operated on freon R12.
☑️ How to find information about gas
Problems with refrigerant and signs of a leak
The most common gas-related problem is a leak. Since the system is sealed, the gas should not disappear on its own. If the refrigerator has stopped freezing and the compressor is running non-stop or, conversely, is silent, this is a sure sign of a circuit malfunction. Leaks often occur in places where pipes are soldered or due to corrosion of the evaporator, especially if you tried to tear off the ice with a knife.
Symptoms of a lack of refrigerant are:
- 🌡️ The temperature in the chambers is higher than the established norm, food spoils.
- 🔊 The compressor hums continuously, trying to gain temperature, but does not turn off.
- 💧 There is no ice or “snow coat” on the back wall inside the chamber (in models with a drip system).
- 🔥 The condenser (grid at the back) remains cold or warm only partially.
Another problem may be a clogged capillary tube or moisture entering the system, which changes the properties of the refrigerant and requires a complete refill. In such cases, the technician does not simply add gas, but evacuates the system to remove air and moisture, and then refills a strictly defined amount of the substance.
Refilling cost and repairs
Repairing the cooling system with replacing or refilling gas is not a cheap procedure. The cost consists of the work of the technician, the cost of refrigerant, oil and consumables. The type of gas affects the price: R600a cheaper to purchase, but requires more careful handling, which may be reflected in the prices of service centers. R134a also available, but requires a more powerful vacuum pump.
The repair process usually includes finding the location of the leak (often using a leak detector or soap solution), eliminating the defect soldering, installing a new filter-drier, long-term vacuuming and filling by scale. The weight of the refill is critical: excess gas will lead to high pressure and breakdown of the compressor, and too little will lead to ineffective operation.
Is it worth repairing an old refrigerator? If the leak occurs in the foamed part of the housing (the evaporator inside the wall), repair is often not economically feasible. In such cases, experts suggest installing an external evaporator (“crying” on the back wall), which is cheaper, but spoils the appearance and reduces the usable volume.
Is it possible to fill a refrigerator with gas from a lighter?
It is absolutely not possible. Lighter gas is purified butane, but it does not contain the necessary lubricating additives for the compressor and may contain impurities that destroy the system. In addition, the pressure and thermodynamic properties of pure butane differ from brand R600a, which will lead to incorrect operation of the unit.
Why does the refrigerator freeze worse after refilling?
This may mean that there is air left in the system (poor evacuation) or the dose of gas is incorrect. It is also possible that the technician used the wrong type of refrigerant or did not replace the filter drier, and now the system is clogged with moisture or oil breakdown products.
Is freon R134a dangerous when inhaled?
In high concentrations, it displaces oxygen, causing suffocation. Also, upon contact with an open flame, it decomposes to form phosgene, a chemical warfare agent. However, in domestic conditions, if there is a small leak from a household refrigerator, serious poisoning will not occur; it is enough to simply ventilate the room.
How long does the gas last in the refrigerator?
The service life of the refrigerant is not limited. If the system is sealed, gas will circulate in it for 10, 15 and even 20 years without loss of properties. It does not “wear out” and does not require scheduled replacement, like oil in a car.