Disposal of old household appliances often poses the owner with the question of where to put the released components. A particularly valuable resource is the copper coil, which previously circulated the refrigerant. This element is a long tube, rolled into a spiral, and contains pure copper, non-ferrous metals and sometimes aluminum.
It is the high thermal conductivity and plasticity of the material that make it an ideal raw material for many home projects. Copper coil can be turned into an effective heat exchanger, decorative lighting element, or even used in alternative energy systems. However, before starting work, it is necessary to take into account the technical features of the alloy and the chemical residues inside the tubes.
In this article we will look in detail at how to properly remove the part, how to clean the internal cavity from freon and oil, and also consider the most popular and safe options for its reuse. Proper preparation is a guarantee that reuse will not will harm neither the health of the master nor the environment.
Removal and initial preparation of the component
The dismantling process begins with completely disconnecting the refrigerator from the power supply. It is necessary to remove the rear metal panel covering the compressor and condenser grille. Typically, the coil is integrated into a black grille on the back wall or hidden inside the side panels of the case in models with a foamed condenser.
To remove it, you will need a hacksaw or a pipe cutter. Pipe cutter is preferable, since it gives an even cut without chips, which are then difficult to blow out. Cut off the inlet and outlet tubes, being careful not to damage the spiral itself. If the condenser is foamed, you will have to carefully open the insulating layer to get to the copper.
⚠️ Attention: Residual pressure and refrigerant vapor may remain inside the tubes. Make the first puncture or cut in a well-ventilated area, away from open flame, since some types of freons can form toxic compounds upon contact with the surface.
After physical removal, the part is a dirty, often oxidized structure. At this stage it is important to determine the type of metal. Pure copper has a characteristic reddish tint and is not magnetic. If the tube is silver and is magnetic, it is coated steel, and if it is light and not magnetic, it is aluminum. Aluminum coils are less valuable for processing and more difficult to solder.
Cleaning from technical oils and contaminants
The inner surface of the tubes is always covered with a thin layer of compressor oil, which circulated along with the refrigerant. For use in food applications (e.g. distillers) or heating systems, this substance must be completely removed. Simple washing with water will not help here, since the oil is hydrophobic.
The most effective method is calcination or chemical washing. Calcination involves heating the entire structure with a burner until red to burn off the organic matter. However, this method can lead to oxidation of the copper and the formation of scale inside, which will then have to be washed out with acid. A more gentle option is to use solvents.
⚠️ Attention: Do not use aggressive acids for cleaning if you plan to use the coil for food purposes. It is almost impossible to wash out acid residues from a long spiral tube, which will lead to poisoning.
For chemical cleaning, you can use regular Galosh gasoline or specialized degreasers. The liquid is poured inside, the tube is shaken, and the process is repeated several times until the escaping solvent becomes transparent.
☑️ Checking the cleanliness of the coil
Do-it-yourself moonshine still
The most popular option for using a copper spiral is to create moonshine still or its part - the refrigerator (condenser). Copper has bactericidal properties and perfectly binds sulfur compounds, improving the quality of the final product. The length of a standard refrigeration coil (usually 5-8 meters) is quite sufficient for a home distiller.
To assemble the structure, you will need a container (tank) in which the spiral will be placed. A cold tap or ice stream of water should circulate through this container. Alcohol vapor, passing through the inside of the coil, is cooled by the walls and condenses into liquid.
Why copper?
Copper catalyzes the oxidation of aldehydes and the removal of sulfur compounds that are formed during fermentation. This makes the drink softer and eliminates unpleasant odor, which is especially important when distilling fruit and grain mash.
It is important to ensure the tightness of the connections. For this purpose, food grade silicone hoses and clamps are used. Steam is supplied to the spiral inlet (from below), and condensate flows from above. The counterflow of water in the cooling jacket (from bottom to top) increases the efficiency of the process.
Use in heating systems and alternative energy
High heat transfer makes the coil an excellent candidate for creating heat exchangers. Home craftsmen often build such spirals into solid fuel boilers to increase their efficiency or use them as radiators in natural circulation systems.
Another interesting application is a solar collector. The coil is painted black with heat-resistant paint, placed in a glass box with thermal insulation, and water is run through it. Heated by the sun, such a system can provide the house with technical hot water in the summer.
When used in heating systems under pressure, it is necessary to take into account that thin-walled refrigerator tubes are not designed for high pressure (more than 3-4 atmospheres). Hydraulic hammer may break the structure. Therefore, such homemade products are more often used in gravity (gravity) systems or low-pressure circuits.
Decorative products and interior items
If technical application is not part of your plans, a coil can become the basis for a unique decor. Due to its flexibility, copper tube can be given any shape. It is used to create lamp shades, legs for loft-style tables, clothes hangers and even frames for climbing plants.
Copper becomes patina over time, acquiring a noble greenish tint. If you want to maintain shine, the product must be coated with metal varnish. To create lamps, it is important to provide insulation, since copper conducts electricity.
Technical characteristics and compatibility table
Before starting the project, it is worth assessing the parameters of your existing coil. They may vary depending on the capacity and year of manufacture of the refrigerator. Below is a table with indicative data.
| Parameter | Value / Description | Impact on application |
|---|---|---|
| Material | Copper (M1, M2), Aluminum, Steel | Copper is ideal for soldering and food purposes, aluminum is difficult to solder |
| Tube length | From 4 to 10 meters | Determines heat transfer area and performance |
| Diameter | 3-6 mm (internal) | Affects the throughput of liquid/steam |
| Melting point | ~1083°C (copper) | Allows use in high-temperature units |
When choosing a project, focus on the integrity of the tube. If kinks or microcracks form during extraction, using the element in systems with liquid can be risky. Tightness is a key factor in the success of any engineering homemade product.
Safety and environmental aspects
Working with used parts requires precautions. As mentioned earlier, freon and oil residues can be harmful. In addition, when soldering copper tubes, it is necessary to use fluxes that do not contain chlorides (for example, rosin) if the product comes into contact with food products.
Disposal of residues (clippings, chemicals) should be carried out responsibly. Do not pour flushing solutions down drains or onto the ground. Collect them in containers and hand them over to a hazardous waste collection point.
☑️ Safety rules when working
Frequently asked questions (FAQ)
Is it possible to solder a coil with tin?
Yes, copper can be soldered perfectly with soft materials solders (tin-lead or lead-free). However, for food purposes (moonshine), it is better to use refractory solders with silver or phosphorus, since they are stronger and safer at high temperatures.
How to determine whether the coil is copper or aluminum?
Scratch it with a knife in an inconspicuous place. If the color does not change under the scratch and the metal is soft, it is copper. If the color is silver and the metal is harder - aluminum. You can also use a magnet: copper and aluminum are not magnetic, steel is.
Is it necessary to tin the coil from the inside?
For distillation, tinning is not required and is even undesirable, since pure copper interacts better with alcohol vapor. For heating systems, tinning can protect against corrosion, but it is difficult to implement over long sections.
How much does it cost to scrap a coil?
The price depends on the exchange value of copper at the moment and the point of collection. Copper is generally more expensive than aluminum and steel. Before handing over, make sure that there are no oil residues inside; for this they may reduce the price or not accept the scrap at all.
Is the coil suitable for a water heated floor?
Theoretically, yes, but this is economically impractical and technically risky. Thin walls may not withstand the pressure in the central heating system, and high heat transfer from copper can lead to uneven heating of the floor.