There are countless applications where compressed air must be generated to achieve the desired result. The air compressor makes it possible, but depending on the application, a specific type of compressor is used. If you want to buy a compressor for private use, you should first think about what you need an air compressor for.
This article will help you find out which model is suitable for your individual application. Do you want to inflate balls or use a beater?
In our air compressor test 2021 we answer your questions about buying an air compressor. We present detailed information on the topic of air compressors, as well as different types of compressors and explain some criteria that you can use to choose the right device for you.
- 1 Weekly newsletter with the best personal finance tips
- 2 Summary
- 3 The Best Air Compressor: Our Picks
- 4 Guide: Questions you should ask yourself before buying an air compressor
- 5 Decision: What types of air compressor are there and which one is right for you?
- 5.1 What distinguishes a classic piston compressor and what are the advantages and disadvantages?
- 5.2 What are the characteristics of a screw compressor and what are the advantages and disadvantages?
- 5.3 What are the characteristics of a mini compressor and what are the advantages and disadvantages?
- 6 Buying criteria: You can use these factors to compare and evaluate air compressors
- 7 Facts worth knowing about air compressors
- There are many different compressors. You can buy small compressors for inflating car tyres or portable compressors that you can also use for painting at the same time.
- Compressors use pistons or screws to compress the air that is sucked in and then release it at high pressure. Another name for the compressor is the compressor.
- The price range for new compressors can be from ten euros to over 10,000 euros. One of the most important criteria when buying is the working pressure, but the devices also differ greatly in quality and features.
The Best Air Compressor: Our Picks
Guide: Questions you should ask yourself before buying an air compressor
What is an air compressor?
In the professional sector, compressors or also compressors, air compressors and air compressors are used to drive machines, air conditioning compressors, refrigeration dryers or cooling units for various cooling devices.
In the home, you can conveniently inflate everything from inflatable mattresses to car tyres, or even "beef up" the engine power of cars. Even though there are many different types of compressors, they all work on two principles.
According to the principle of displacement, the volume is reduced and the sucked-in air generates pressure. The compressed air is then transferred from the piston to the connected pipe. There is also the so-called turbine principle, where the inhaled air is pressed onto the wheels and from there transferred to the diffuser, where the air is converted into compressed air.
How much does an air compressor cost?
If compressor accessories and compressor spare parts are already included in the compressor kit, you can usually save money. For example, you can buy a screw compressor for less than 200 Euros. But consider what you really need. Many DIYers will use equipment that is cheap but doesn't meet their needs. For all-purpose compressors, you need to budget between 40 and 150 euros.
What is important in an air compressor?
More powerful air compressors with a higher quality are generally more expensive, but also more durable. This investment is especially worthwhile if you plan to use the compressor for several years. Since the devices can sometimes even last for decades, they hardly ever need to be replaced.
With or without oil, screw pistons or reciprocating pistons, these specific problems can sometimes only be clarified during a professional consultation. Experienced craftsmen have the necessary knowledge to find the best air compressor for them. For laymen, however, professional guidance is helpful.
What alternatives are there to an air compressor?
On the one hand, the focus is on cost optimisation; on the other hand, important work processes should be taken into account. For some work, compressed air systems are still considered particularly powerful and practical.
For cleaning tasks, mechanical alternatives can be used instead of air compressors. Compressed air is much more expensive compared to mechanical brushes or other cleaning equipment. For this reason, the speed of the air compressor is much faster in comparison.
Which alternatives come into question depends on the application area and your own requirements. A manual spray gun may be sufficient to complete the spraying process, but you must also be able to handle it properly to achieve consistent results. Therefore, various electrical and mechanical alternative air compressor solutions must always be reviewed with a certain degree of predictability. In some cases, when low to medium power is required, some wireless tools can also replace the compressor.
Decision: What types of air compressor are there and which one is right for you?
If you want to buy an air compressor, you can choose between three different types:
- classic piston compressor
- Screw compressor
- Mini compressor
Before you buy an air compressor, you should know the different types of compressors. You can find the most important types in the following overview.
What distinguishes a classic piston compressor and what are the advantages and disadvantages?
Piston compressors are the classics among compressors and are the most commonly used. The compressor works oil-free and according to the displacement principle. The air is sucked in, the gas inside is displaced and compressed.
The pressure rises and ensures that the compressed air is forced out. The special feature of the piston compressor is that it is operated with a relatively low volume flow, but the internal pressure generated is still high. This makes the piston compressor very effective.
What are the characteristics of a screw compressor and what are the advantages and disadvantages?
Screw compressors are the second most common type of compressor, but unlike piston compressors they work according to the turbo principle. As the name suggests, this air compressor is particularly powerful. An overpressure of 30 bar is generated. For this reason, it is used where excellent performance is required, for example when adjusting car engines.
What are the characteristics of a mini compressor and what are the advantages and disadvantages?
The mini compressor is much smaller and more convenient than ordinary compressors. If you want to inflate a ball, a bicycle or a car tyre, this easy-to-carry, quiet and efficient compressor is suitable for that. Because of its mobility, it is also very suitable as an airbrush.
Buying criteria: You can use these factors to compare and evaluate air compressors
In the following, we show you which aspects you can use to choose from the many air compressors.
The criteria you can use to compare air compressors include:
In the following sections we explain what individual criteria are important.
In terms of power, there are significant differences between the different types.
Although the power of battery-powered compressors or micro compressors is only sufficient to expand the air cushion or ball, many large air compressors have far more than 1,000 watts. These models can even be used as spray gun compressors or various tools to use compressed air.
Good units can hold 40 litres of water per minute, and the top models even exceed 200 litres.
Another important performance feature is the maximum suction power. This also depends on the type of compressor, where the power of micro or battery compressors is often low as well. The suction affects the amount that the compressor can compress and eventually discharge.
The higher the pressure, the greater the quantity discharged. The maximum capacity indicates how much air the compressor can deliver at the highest possible pressure. A good value is 80-100 litres. Top equipment can produce more than 200 litres of flow per minute.
Compressor pressure is an important factor in its performance and applicability. If you only want to use the air compressor for small jobs or to inflate tyres, you only need a low pressure. However, for more demanding tasks, the air compressor pressure will increase slightly.
In most compressor tests, another important point is the maximum pressure the compressor can reach. As an example: the gun compressor should be able to generate a pressure of ten bar. You don't need a 10-bar compressor to inflate bicycle tyres, as four are sufficient.
The following information on the required air pressure is for reference only:
|Inflate balls or bicycle tyres||2 - 4 bar|
|Inflate car tyres||3 - 6 bar|
|Tack with pneumatic tacker||6 - 10 bar|
|Use impact wrench or sandblaster||8 - 10 bar|
The size of the boiler is the basis for the overall size of the air compressor. For household manometers, the maximum size of the air receiver is 50 litres. In home decoration, 6, 9 or 24 litre air compressors are commonly used. If the compressor volume is 50 litres or more, it is also suitable for professional use.
The mini compressor without air tank can be used for small handicrafts or for inflating balls and inflatable mattresses. Some of these practical compressors can be used with batteries. With the compressor of a 6-litre mini-compressor, you can also do airbrush work or model-making work.
To inflate car tyres, however, you need a larger unit, as you need at least a fuel tank with a capacity of 24 litres. For units up to 24 litres, the maximum pressure is 8 bar, and only a small amount of air can be stored. If you use air tools for a longer period of time, the tank will be permanently charged, which will cause a lot of noise. Small units have a compact, practical design and flexibility.
What should be the weight of an air compressor? The weight of the air compressor determines its possible use and influences its flexibility. The small model weighs less than 3 kg, while the standard unit weighs about 20 kg. Large air compressors usually weigh more than 40 kg.
- Mini compressor: The small practical mini compressors range from 2-4 kg.
- small piston compressor: The piston compressors have an average weight of 15-25 kg.
- large piston compressor: The larger version of the piston compressor has an average weight of 25-35 kg.
- Screw compressor: The heaviest version of a compressor is the screw compressor with an average weight of 40-60 kg.
The weight of the compressor also depends on the construction. This is especially important if you often carry a portable compressor. However, don't forget that larger and heavier units are also more powerful.
When you buy a portable compressor, it usually comes with wheels. However, if you get a model without wheels, be aware of the weight. Compressors generally weigh quite a lot. However, there are differences.
The volume of an air compressor is very device-dependent and can sometimes exceed 100 dB. Some manufacturers use special rubber coatings to reduce vibrations and noise. For example, additional quiet compressors have been developed that are kept below 50 dB and still have an impressive performance. Operating noise does not always translate into performance, but you should expect quieter models to cost more.
The volume of an air compressor results from the constant inflation that is inevitable when using these devices. To produce sufficient air pressure, a correspondingly high force is required. The noise can only be reduced by damping the device.
Particularly quiet air compressors are models without an air tank. Some piston compressors are relatively quiet even with an air tank. In contrast, the rotary model is louder due to its special design. If you use a rotary compressor, you should therefore wear hearing protection.
Facts worth knowing about air compressors
How does an air compressor work?
We show here which settings can be made and which applications are suitable for an air compressor. For some tools, a reliable compressor is essential. In order to adapt it to their respective building and hobby projects, specific preparation is necessary.
The instructions compiled here should help you to carry out the necessary steps before using the compressor. This is the only way to set the compressor pressure correctly. If the air pressure is too low, the air tool will not have the required power. If it is too high, this can lead to work hazards.
- Read through the instruction manual: First, it is important to read through the instructions and look at the sketch of the unit design. If you have a general understanding of the design and function of an air compressor, you will have a better understanding of how the equipment works and what to look for. It is also useful to know the exact layout of the attachment.
- Open the cover of the pressure switch: Remove the cover of the air compressor from the pressure switch. You only have to loosen the corresponding screws. Then you can easily remove the cover.
- Select the automatic position: Now switch the on/off switch to the automatic basic setting. Depending on the compressor type, the normal opening position is also an automatic position. This ensures that the compressor runs until it is switched off again.
- Check the pressure display: When the air compressor is automatically switched off, the pressure display must be checked and the status recorded. This shutdown pressure setting helps control the pressure level.
- Let the air out: The next step is to deal with the main task of the compressor, which is to let the air out selectively. To do this, connect the hose to the appropriate unit. This can be done with the appropriate connector that you push into the compressor nozzle. Then open the air tool at the other end of the air hose. When the handle is now activated, compressed air will come out of the tool.
- Build up new pressure: After the pressure has decreased, the pressure increases again. To do this, turn the calibration screw clockwise. Normally, the screw is located near the differential adjustment screw. On some compressors there is only one screw. If in doubt, read the instruction manual or seek information from an expert to avoid turning another screw. If you turn to the right, the pressure will increase and vice versa. With a little attention and talent, you could repeat the steering process many times until you find the right opening pressure.
How is an air compressor powered?
Remember that the engine only works when there is combustion. This can only be ensured by a sufficient supply of oxygen. The air compressor is basically a compressor driven by a motor. The integrated compressor wheel draws in outside air and compresses it inwards. In this way, the combustion effect can be improved in a conventional petrol engine, for example.
It should be noted that the gas or medium is always heated to a certain temperature during compression. In modern and more powerful compressors today, however, only a relatively small amount of heat is dissipated, which is ultimately not used. A real plus for the environment.
Another important function of the compressor is to reduce the volume flow as much as possible under the condition of high pressure utilisation, which means that the highest power can be set but only a small amount of air is required.
It is also important that air compressors operate as quietly and evenly as possible. This is the only way to achieve a good quality of work.
What are useful accessories for an air compressor?
In order to use the air compressor effectively, it is recommended to prepare certain accessories and spare parts. You can easily buy these spare parts and accessories in a DIY store.
|compressor hose||Nothing works without a compressor hose. Therefore, it is best to have several sizes in your inventory. You can buy hoses individually or in complete sets, for example with a compressed air knife. Compressed air barrels are also very practical, allowing you to easily roll up long hoses.|
|Inflation adapters||Inflation adapters are needed for various uses. You need different adapters to inflate or even deflate. Suitable sets containing the common adapters are already available on the market for little money.|
|Sandblasting gun||Sandblasting guns are a good tool for removing old paint from fences, wooden floors or garden sheds.|
|Airbrush gun||The airbrush gun is the ideal accessory for artists. Use the equipment together with the accompanying spray gun as a spray gun compressor.|
|Compressed air tools||This is how you make your compressor an indispensable helper in the craft sector. Air tools are usually more efficient and durable than power tools and can usually be bought in sets that include air spanners, ratchets, chisels and bar grinders, for example. However, for these tools you will need a more powerful air compressor.|
When does an air compressor need to be inspected?
In addition to companies and industries, more and more people are using air tools. Basically, however, these operations are rarely carried out by private users.
However, since the compressor can build up a pressure of 10 bar in the pressure accumulator even with smaller tools, its explosive power is almost equivalent to that of 17 fireworks. Therefore, the compression should only be used according to the manufacturer's instructions.
Each federal state has its own regulations, which are checked by monitoring authorities such as TÜV or DEKRA.
Commercial compressors with a capacity of 50 litres or more must be commissioned by an authorised monitoring body before first use. Qualified personnel can test the compressed air of a compressor with up to 1000 l / bar. All of the above are considered a system that must be monitored by an authorised body.
Which oil is suitable for air compressor?
You can also choose an oil-free air compressor. However, most compressors are operated with oil. However, you should not use the same compressor oil for all models.
The most important feature is the correct viscosity. The oil must not be too viscous or too liquid. The reciprocating piston in the compressor can only function properly if the correct lubricating film is used.
If you use the compressor regularly and often, you should follow the manufacturer's instructions on the types of oil available. These can be found on the fuel connection of your air compressor. In rare cases, conventional compressor oil can also be used.
Image source: Petchmai/ 123rf.com