The failure of a refrigerator is always a nuisance that requires financial investment or complex repairs. However, for a home handyman, the breakdown of household appliances means the emergence of a valuable source of spare parts, among which compressoroccupies a central place. This unit has a huge margin of safety and is able to work for years, creating high pressure or vacuum.
Many people throw away the old unit, not even suspecting that a powerful tool for the garage or workshop is hidden in its case. You can use it to assemble an airbrush for painting, a compressor for inflating tires, a vacuum sealer, or even an aeration system for an aquarium. The main thing is to understand the principle of operation and observe safety precautions when altering.
In this article we will analyze the most popular and functional options for using a decommissioned motor. You will learn what tools are required for modernization, how to properly connect the components and what nuances should be taken into account so that the homemade product lasts a long time. Sealed compressors from refrigerators of the brand Atlant, Donbass or imported brands like Electrolux almost identical in design, which makes the instructions universal.
Design features and preparation of the compressor
Before you begin assembling homemade products, it is necessary to remove the unit from the refrigeration unit and troubleshoot it. A standard piston compressor is a sealed casing containing an electric motor and a crank mechanism. There are usually three pipes on the body: two for freon (inlet and outlet) and one sealed process pipe.
The first step is to determine which pipe is suction and which is discharge. To do this, just briefly plug in the device (being careful!) and place your finger near the holes. Where the air is blown out with force, there is an exit. Where the finger sticks is the inlet. Process pipe most often used for refilling with freon, but in homemade products it can be used to install a pressure gauge or valve.
It is important to check the performance of the oil inside the system. If the compressor lay idle for a long time or was torn off with broken tubes, the oil could oxidize or leak. For full operation as an air blower, it may be necessary to replace the oil with a more heat-resistant one or replace it completely if the old one has turned black. You should also clean the outer part of dirt and rust in order to have access to the threaded connections.
⚠️ Attention: It is strictly forbidden to open the sealed compressor casing with a grinder or a hacksaw if you plan to use it as a pump. Inside there is an inert gas or refrigerant vapor, as well as oil vapor under pressure. Opening will lead to irreparable damage to the unit as pumping equipment.
To connect to the power supply, you will need a starting relay, which is usually attached to the side of the housing. This is what ensures the engine starts. If the relay is burned out or lost, it will have to be replaced with a similar one, selected according to the engine power. There is often a marking on the relay body, for example, P-1 or R-6, which will help you find a replacement.
Assembling a homemade compressor for an airbrush
One of the most popular devices among modelers and artists is a compressor for airbrushing. Factory models are expensive, while a homemade version using a refrigeration motor is much cheaper and operates quieter. The main task here is to ensure an even flow of air without pulsations, which can ruin the paint job.
To implement the project, you will need a receiver. An old fire extinguisher, a gas cylinder, or even a thick plastic canister is ideal as a container for compressed air (although metal is more reliable). Air from the compressor is first pumped into the receiver, and from there it enters the airbrush through the gearbox. This smoothes out piston jerks and stabilizes pressure.
The assembly process is as follows:
- 🛠️ An adapter for a hose or copper tube is installed on the compressor outlet.
- 🛠️ The hose is connected to the inlet of the receiver, where it must There should be a check valve so that the air does not flow back into the motor.
- 🛠️ At the outlet of the receiver, a reducer with a pressure gauge is mounted to adjust the paint supply pressure.
- 🛠️ The entire system is connected to the starting relay and a cord with a plug.
Special attention pay attention to filtration. The air coming out of refrigeration compressorcontains microscopic droplets of oil. This is unacceptable for airbrushing, as oil will get on the surface of the product. A moisture-oil separator must be installed between the receiver and the airbrush. It can be bought ready-made or made from a transparent flask with filler.
☑️ Assembling the compressor for painting
The finished device is much quieter than its industrial counterparts, since the housing of the refrigeration motor itself is an excellent sound insulator. However, during prolonged operation it can heat up, so it is recommended to provide ventilation holes in the casing or housing of the future installation.
Vacuum food sealer from an old motor
A refrigeration compressor by its nature is an excellent vacuum pump. If you confuse the input and output, it will begin to pump out air rather than pumping it. This feature can be used to create a vacuum sealer, which will extend the shelf life of products significantly.
To create a vacuum sealer, you will need a sealed chamber. In the simplest version, it can be a thick plastic container with a lid into which a fitting is mounted. The hose from the fitting is connected to suction pipe the compressor. A hose that goes into the atmosphere is put on the outlet pipe (which now works for blowing).
The packaging technology is simple:
- The products are placed in a special bag with a zip fastener or in a container.
- The package is placed in the chamber or connected by a tube to the system.
- A compressor is turned on, which pumps out air, compressing the product tightly.
- After achieving the desired vacuum, the package is sealed or the valve is closed.
It is important to understand that refrigeration compressors are not designed to create deep vacuum on an industrial scale. They do an excellent job with everyday tasks, but can overheat when operating in vacuum mode for a long time. It is recommended to take breaks from work every 15-20 minutes.
Is it possible to pump out water with a compressor?
No, absolutely not. The compressor is intended for gaseous media only. If liquid gets inside, it will cause water hammer and instant failure of the valves or connecting rod. To pump out liquids, use special pumps.
Compressor for inflating tires and pneumatic tools
The most practical application for motorists and home craftsmen is the creation of a full-fledged compressor station. It will allow you to inflate tires, work with a pneumatic impact wrench, spray gun, or blow dust out of complex components. The power of a standard refrigerator motor is quite sufficient for most garage tasks.
The key element here is a large-volume receiver. To inflate tires, it is recommended to use a cylinder with a volume of 20 liters or more. This will provide a supply of air that allows you to work with pneumatic tools, which consume a lot of energy. A small receiver will cause the motor to turn on and off too often, which will quickly wear out the starting relay.
The equipment connection diagram looks like this:
- 🔧 The compressor supplies air to the lower part of the receiver through a check valve.
- 🔧 It is installed at the bottom point of the receiver tap for draining condensate, which inevitably forms when air is compressed.
- 🔧 A safety valve is placed at the outlet, which bleeds air if the pressure exceeds the permissible level (usually 8-10 atmospheres).
- 🔧 Next comes a pressure gauge and a splitter with quick-release connections for hoses.
⚠️ Attention: The pressure that the refrigeration unit develops compressor can reach 20-25 atmospheres and higher, which is dangerous for thin-walled containers. Use only certified gas cylinders or fire extinguishers with a safety margin. Plastic canisters are absolutely not suitable for creating pressure!
For ease of operation, the system can be equipped with automation. The pressure switch (pressure switch) will automatically turn on the motor when the pressure in the receiver drops below the set minimum, and turn it off when the maximum is reached. This turns the homemade product into a professional tool that does not require constant monitoring.
Aeration systems and other unusual applications
In addition to the obvious use as a pump, the compressor can become the basis for water aeration systems. In aquarium and fish farming, it is important to saturate the water with oxygen. The power of even a small motor is enough to service several aquariums or a large pond through a system of hoses and sprayers.
Another interesting idea is to create a forge for blacksmithing or smelting metals. By supplying air under pressure into the furnace, the combustion temperature of coal can be significantly increased. This does not require high pressure, the volume of pumped air is important, which the refrigeration unit copes with excellently.
Let's compare the main parameters of the resulting devices in the table:
| Parameter | Airbrush | Vacuumator | For tires | Aeration |
|---|---|---|---|---|
| Pressure | Low (up to 2 atm) | Vacuum | High (up to 8 atm) | Minimum |
| Receiver | Required (5-10 l) | Not required | Required (20+ l) | Not needed |
| Filtration | Critical (oil/water) | Not critical | Desirable | Not needed |
| Noise | Important (quiet running) | Average | Not important | Not important |
You can also make an air gun from a compressor for recreational shooting or carpet cleaning device. The imagination of masters is limited only by the available space and the need to comply with the laws of physics. The main thing to remember is that performance such motors are small, so they are not suitable for industrial volumes of work.
Maintenance and safety measures
Homemade devices based on a refrigeration motor require regular maintenance. Unlike factory appliances, here you are fully responsible for safety. First of all, check the electrical part: all contacts must be reliably insulated, and the ground must be connected, especially if the device will operate in a damp garage.
The oil in the compressor loses its properties over time, especially if the device works more intensely than in the refrigerator. It is recommended to check the oil level and condition through the process pipe once a year (if there is access) or simply monitor the housing temperature. If the motor starts to hum louder than usual or gets very hot, this is a signal for prevention.
Basic rules for safe operation:
- ⛔ Do not leave a running compressor unattended for a long time.
- ⛔ Regularly drain condensate from the receiver to avoid corrosion containers from the inside.
- ⛔ Monitor the tension and integrity of the electrical cable.
- ⛔ Do not exceed the maximum operating pressure specified for your type of receiver.
⚠️ Attention: When working with pressure receivers, there is a risk of explosion due to corrosion or damage to the walls. Before installing the cylinder (fire extinguisher), make sure there is no deep corrosion. If you have doubts about the integrity of the metal, do not use this container.
Regular cleaning of the air filters at the compressor inlet will extend the life of the piston group. Dust, getting inside, acts as an abrasive, accelerating the wear of cylinders and rings. A simple piece of foam rubber or a car filter at the inlet works wonders.
Frequently asked questions (FAQ)
How many atmospheres can a regular refrigerator produce?
A standard household compressor is capable of creating a pressure of 20 to 25 atmospheres or more. However, for the safe operation of home-made devices, it is recommended to limit the pressure to 6-10 atmospheres using a reducer and pressure switch, since hoses and connections may not withstand more.
What oil is best to pour into a converted compressor?
It is best to use special synthetic oil for compressors (compressor oil). Regular motor oil is not suitable for cars, as it can foam or coke at high temperatures inside the sealed casing. If the compressor is new, you don’t need to change the oil.
Why does the compressor hum but does not start?
Most often the problem is in the starting relay or capacitor. It is also possible for the piston group to jam due to lack of oil or prolonged parking. Sometimes a “ping” (short-term supply of voltage bypassing the relay) helps, but this is a temporary measure.
Is it possible to use a compressor from a No Frost refrigerator?
Yes, you can. Compressors from No Frost systems often have a little more power, but the principle of their operation and connection is identical to conventional models. The only difference is that they may be more sensitive to overheating, since in the No Frost refrigerator they operate in a more gentle mode.
Is a receiver needed to inflate tires?
Technically, you can inflate directly, but it will be very slow and inconvenient, since the performance of the refrigeration motor is low. The receiver accumulates air, allowing you to create a short-term powerful flow to break the wheel or quickly pump it up, after which the motor calmly fills the tank again.