The question of the content of non-ferrous metals in household appliances often arises not just out of curiosity, but when planning disposal or handing over old equipment to scrap collection points. A refrigerator compressor is a sealed metal cylinder, inside of which valuable raw materials are hidden, in particular copper and aluminum. However, the exact weight of copper in a compressor from a refrigerator is not a constant value; it varies depending on the year of manufacture, model of the unit and production technology.
Many people mistakenly believe that the entire body or a significant part of it consists of pure non-ferrous metal, which leads to inflated expectations when weighing. In fact, the lion's share of the mass comes from steel, which is used to create a durable casing that can withstand high refrigerant pressure. Copper is concentrated in the electric motor windings and heat exchange tubes, making up only a percentage of the total weight of the device.
In this article we will look in detail at what the amount of copper depends on, how the marking of the compressor affects its internal contents and why when disassembling it is important to take into account not only the yield of metal, but also the safety of the process. Understanding the design will help you realistically estimate the potential profit from scrap.
Design features and distribution of metals
To understand how much copper is inside, you need to look at the design of a typical reciprocating compressor. The sealed housing, often called a "pot", is made of stamped steel, painted with enamel to protect against corrosion. Inside this casing there are two main components: an electric motor and the compressor mechanical part itself. It is electric motor that is the main consumer of copper in this assembly.
The motor stator winding is made of copper wire, since this material has the best electrical conductivity among the available industrial metals. The number of turns and thickness of the wire depend on the power of the motor. The more powerful the compressor, the larger the diameter of the wire and, accordingly, the higher the weight of the copper component. However, in modern models, manufacturers often strive to minimize the use of expensive resources.
Heat exchange tubes going outside can also be made of copper or aluminum. Old Soviet refrigerators used predominantly copper, while modern budget models (especially those made in China) increasingly use aluminum or steel. This significantly reduces the final yield of non-ferrous metal during processing.
⚠️ Attention: There is oil inside the compressor, which can be toxic or aggressive. When cutting the case yourself, be sure to use personal protective equipment and carry out work in a well-ventilated area or outdoors.
It is also important to note that the weight of copper directly correlates with the energy efficiency class of the device. Older models that consume a lot of power often have heavier pure copper windings. New inverter models may be more compact, but their internal electronics contain less metal and more complex alloys.
Factors influencing the weight of copper in a compressor
The answer to the question “how many kg of copper” cannot be a single-digit number without taking into account several critical parameters. The first and most important factor is year of manufacture refrigeration equipment. In Soviet times, when the cost of resources was not a determining factor in the economy, manufacturers did not save on non-ferrous metals. The windings were made with a margin of safety and from pure copper.
The second factor is the country of origin and brand. European models (for example Electrolux, Beko old model) and Soviet units (Atlant, Zil, Oka) traditionally contained more copper compared to modern Asian counterparts. Chinese manufacturers, in pursuit of cost reduction, are actively introducing aluminum windings, which are visually difficult to distinguish from copper ones without checking with a magnet or on a cut.
The third factor is the type of refrigerant and operating pressure. Compressors operating with R600a freon (isobutane) often have lower power and, accordingly, less copper in the windings compared to units using R134a. However, this difference is not always dramatic, since the main dimensions of the engine remain similar.
It is also worth considering the technical condition. If the compressor burns out, copper remains in the windings, but its removal may be difficult due to melting of the insulation. If the device was opened earlier and “burnt out” in a handicraft way, part of the metal could be lost or oxidized, which would reduce its weight and cost.
Accurate data: table of copper weight by model
Based on the analysis of many disassembled units and data from procurement points, it is possible to derive average copper content values. Remember that we are talking specifically about pure copper in the windings, without taking into account the steel housing, shafts and plates of the electric motor.
The data in the table is given for assembled compressors (the weight of the compressor itself) and the approximate yield of copper with ideal cutting. Actual figures may vary between 10-15% depending on the specific modification.
| Model / Type of compressor | Total compressor weight (kg) | Approximate weight of copper (kg) | Percentage of output (%) |
|---|---|---|---|
| Soviet (Atlant, Zil) | 9.0 – 11.0 | 1.2 – 1.5 | ~12-14% |
| European (Danfoss, Secop) | 8.5 – 10.5 | 0.9 – 1.2 | ~10-11% |
| Modern (LG, Samsung) | 7.5 – 9.5 | 0.6 – 0.9 | ~7-9% |
| Budget Chinese (aluminum winding) | 7.0 – 8.5 | 0.1 – 0.3 (or 0) | ~1-3% |
As can be seen from the table, the spread can be twofold. Old heavy "pots" weighing 10-11 kg are the most valuable for non-ferrous metal mining. Modern lightweight models weighing 7-8 kg often contain a minimum of copper or its substitutes.
⚠️ Attention: Do not try to determine the winding material by the weight of the compressor assembly. An aluminum motor can weigh the same as a copper one due to the use of a thicker steel core or changes in the shaft design.
Why do new models have less copper?
Modern technologies make it possible to create more efficient magnetic circuits and use less conductor while maintaining power. In addition, rising copper prices are forcing manufacturers to look for alternatives, such as copper-plated aluminum or pure aluminum with an increased cross-section.
Methods for determining copper content without opening
Before embarking on the labor-intensive cutting process, many want to assess the potential of the device. There are several indirect signs that suggest the presence of copper. The most reliable way is to check with a magnet. Copper and aluminum are not magnetic, but the steel case hides the insides. However, you can check the protruding tubes: if they are not magnetic and have a reddish tint when cut, they are copper. If it’s silvery and light, it’s aluminum.
The second method is to analyze the markings and year of manufacture. Compressors manufactured before 2000-2005 have copper windings in 90% of cases. Models after 2010-2015, especially the budget segment, require more careful checking. Sometimes the nameplate (sticker) contains an indication of the type of refrigerant used, which indirectly indicates the era and technology.
The third method is cost estimation. If you buy used compressors for disassembly, their price often already takes into account the expected metal yield. If the price is high, most likely the seller already knows about the high copper content. Cheap compressors often turn out to be “dummies” with aluminum windings.
It is also worth paying attention to the brand. Companies like Secop (formerly Danfoss), even in new models, try to adhere to classic technologies, while mass market brands can change component suppliers depending on the exchange rate and the cost of raw materials.
Technology for safe cutting of a compressor
If you decide to extract copper yourself, you will need a set of tools: an angle grinder (angle grinder) with a metal disc, a hacksaw, a hammer, a chisel and protective equipment. The process begins by removing all external elements: relays, start capacitors and copper pipes. The tubes can simply be sawed off or unscrewed if they are threaded (in older models).
Next comes the dirtiest stage - opening the case. It is necessary to make a circular cut with a grinder along the equator of the compressor. Be careful: oil under pressure or vacuum may remain inside. After opening the casing, you will see the “filling”: an electric motor and a cylinder group filled with oil.
To extract copper, you need to get to the stator of the electric motor. It is often easiest to pull out the winding by first cutting one side of the coils with a chisel. Stator is a package of metal plates in which the wire is laid in the grooves. Having cut the connections, the copper can be pulled out with pliers or a hook.
☑️ Safety checklist during disassembly
⚠️ Attention: It is strictly forbidden to open the compressor by burning or heating with an open fire. Remaining freon mixed with oil and air can form an explosive mixture, and oil vapors are toxic. Use only mechanical cutting.
Economic feasibility and ecology
Is the game worth the candle? If you have one old compressor, disassembling it for the sake of 1 kg of copper is unlikely to cover the cost of electricity for the grinder and depreciation of the disk. However, if you are disposing of refrigerators professionally or have accumulated a batch of 10-20 pieces, separating copper becomes economically justified.
Delivering compressors in their entirety (“black scrap” or specific “motor scrap”) often brings less profit, but requires less labor. Reception points can accept them at a separate price if they see that they are old Soviet models. Modern ones often go into the shredder along with the steel.
From an environmental point of view, proper disposal of compressors is critically important. The oil contained inside must not be poured into the drain or soil. It must be collected and transferred for special processing. Freon, even in small residual quantities, is a greenhouse gas that destroys the ozone layer.
In conclusion, the amount of copper in a refrigerator compressor is a lottery, depending on the year and brand devices. Old Soviet units remain a "gold mine" for scrap collectors, while modern equipment requires more complex processing technologies and contains less valuable metal.
Frequently asked questions (FAQ)
Is it possible to determine the amount of copper by the sound of the compressor?
No, the sound of operation depends on mechanical part, valves and housing vibration, but does not correlate in any way with the amount of copper in the electric motor windings. A noisy compressor does not necessarily contain more copper.
What to do with the oil after opening the compressor?
The oil must be drained into a sealed container (plastic bottle or canister) and taken to a waste oil or hazardous waste collection point. It is prohibited by law to pour it into the ground or sewer.
Is there a difference in copper content between R134a and R600a compressors?
There is no direct dependence on the type of freon. However, compressors for R600a (isobutane) are often made less powerful and compact for quiet refrigerators, so the physical size of the winding and the amount of copper in them may be less than in powerful units for R134a.
Will they accept the compressor as scrap if I just cut it in half?
Yes, many collection points scrap metal accepts compressors in disassembled form, separating steel and non-ferrous metal. However, the price for the “mix” (a mixture of metals) will be lower than for copper and steel sold separately. It is better to sort the metals.