In almost every workshop, but also in many private garages, hobby cellars or tool sheds you will find a compressed air compressor. The devices are very versatile in both the commercial and the private sector and accordingly many different models are offered on the market. If you want to buy a compressor, you can lose track of it. We have summarized the most important information about the compressor for you at gmomf.org.
What exactly does the compressor do, what can it be used for and what makes a good compressor? Which compressor is needed for which purpose and what do you have to pay attention to when buying a compressor? In our detailed guide on gmomf.org, we answer these and other questions and introduce you to the best 11 compressors in a detailed comparison.
Top 10 Compressors
Why do you need a compressor?
Compressors are used for many different purposes and can be used both in the commercial and in the private sector. In a workshop that works with compressed air tools, a compressor is indispensable, but also in the private sector, for example, a compressor for car tires performs well. Since compressed air can be used for many different occasions and facilitates many jobs, a good compressor can be used in a very versatile way. Among other things, you can use it for the following work:
- Inflate tires from the car, bike, lawn tractor or other vehicles
- Inflation of leisure items such as balls, air mattresses, paddling pools or swimming pools
- Operation of various compressed air tools, such as impact wrenches or compressed air nailers
- Blow-out works for cleaning
Almost everyone who has a bike, a car or a garden, will find one or the other use for a compressor, in the pure recreational area often only a mini compressor is needed. Do-it-yourselfers, hobby screwdrivers and industrial workshop operators usually do not get around a larger air compressor with a compressed air tank. However, depending on what and to what extent the air compressor is to be used, different criteria must be taken into account when purchasing a compressor. For example, an airbrush compressor should have different characteristics than a compressor that is used in a workshop for the operation of an impact wrench and a compressor that is needed only in the recreational area for inflating paddling pool and the like, will have to meet other requirements again. It is therefore important to always select the compressor according to the intended purpose.
For compressed air compressors, two main types must be distinguished:
- The reciprocating compressor or reciprocating compressor Within reciprocating compressors, a distinction must again be made between reciprocating compressors and rotary reciprocating compressors. As the air in a reciprocating compressor is drawn in and out by a reciprocating piston, the rotary compressor operates with slots through which the air is drawn and expelled. The compression takes place by means of the rotating pistons, which release or close the intake and discharge slots during their movement.
- The Screw Compressor or Screw Compressor The screw compressor uses two rotors for compression, which mesh with a helical toothing. The inflowing air lays tubular around the rotors and is compressed by the rotations as it is pressed into smaller and smaller chambers. When the required pressure is reached, the compressed air is released.
As a rule of thumb, the screw compressor is always the right choice when the compressed air is needed continuously and for longer periods of time. Only then, the screw compressor, which is designed for continuous operation, reaches its operating temperature and can work efficiently. It is, therefore, more suitable for the professional sector and the industry.
The reciprocating compressor, on the other hand, gets along well when it is used again and again for a short time and is often stopped and restarted. For recreational and hobby is therefore usually the reciprocating compressor, the better choice.
Intake power and power output
An important criterion when choosing the right air compressor is the intake capacity. It indicates the amount of air that the compressor can aspirate and is usually given in liters per minute. The intake volume is always higher than the output volume because the air inside the compressor is compressed and the volume is reduced. Of course, the compressor can only work with the air that it has sucked before so that the intake volume gives a good overview of the performance of the device. The more air the compressor can draw in, the more compressed air the compressor can expel, and the output volume will always depend on the degree of compression. Thus, the intake air at a pressure of 5 bar has a higher volume than the same amount of air at 8 bar and the output power is, therefore, a relative value. The suction power, therefore, provides a good comparative value to compare the power of different compression. For the operation of compressed air tools, however, often only the power output is important.
A high intake capacity is therefore not a general feature of a good compressor, because intake capacity and output must always match the intended use of the compressor. For example, an airbrush gun consumes well under 100 liters of air per minute while in operations such as sandblasting, several 100 liters per minute are needed. With regard to the optimum intake and delivery capacity, the future intended use of the compressor must therefore also be taken into account again.
Oil-free or not?
Compressed air compressors are available in oil-free and oil-lubricated variations. When purchasing a new compressor, you must, therefore, decide which variant is better for you. In some areas, this decision is taken from the outset, because for some applications only oil-free compressors are suitable. In the hobby and leisure sector, this is the case especially in these application areas:
- Painting and painting work
- A blow-out on electronic devices
Oil-free compressors are also well suited for the following purposes:
- for inflating tires
- for inflating balls and other recreational items such as wading pools or air mattresses
- for sandblasting
In the commercial sector, oil-free compressors may even be required by law, for example for the following uses:
- in dental medicine
- in the laboratory
- in environmental protection measurement
- in the chemical and pharmaceutical industry
- in electrical engineering
- in the beverage and food industry
The reason for this is that with an oil-lubricated compressor oil gets into the ejected compressed air, which inevitably leads to contamination. Oil-free compressors also have the advantage of being low-maintenance as there are no oil controls and no oil changes. With an oil-free compressor can also save money because the compressor oil is a lot more expensive than conventional engine oil.
On the other hand, oil-free compressors are not suitable for all applications. For example, most air tools need to be run on oil-lubricated compressors because they provide higher speeds and therefore higher output, which is necessary for many air tools. Air drills and other pneumatic tools, for example, need output powers of 150 to 200 liters per minute, which can not be supplied by oil-free compressors due to the significantly lower speeds.
Many air tools also require the oil particles in the expelled air, so that they, in turn, can be lubricated and run smoothly. Although there are compressed air accessories to buy, with which such oil lubrication of pneumatic tools over the air even with oil-free compressors can be made possible, the handling is not very convenient, as they have to be refilled again. For the oil-lubricated compressors also speaks the longer life.
Here too, the future intended use of the compressor largely determines the selection.
Which boiler volume is the right one?
With the exception of small portable compressors, all compressors work with a compressed air tank or boiler. These boilers have different sizes, for example, 6 l, 24 l or 50 l, and the larger the boiler, the heavier the compressor becomes. The reason for this is the pressure that the boiler has to endure. The larger the boiler, the greater the pressure and thus the wall thickness of the boiler must be adjusted accordingly. While a small portable compressor can handle less than 6 kg of weight, a compressor with a 50 l tank volume will easily pack 20 kg or more. For larger compressors with a boiler volume of 80 l, the weight can even rise to more than 50 kg.
The advantages of the compressed air boiler are obvious. The boiler always stores a certain amount of compressed air and only when this air is used up, the compressor starts and compresses further air. The larger the boiler, the greater the reserve of compressed air that can be called up. This has several advantages:
- if a larger amount of compressed air is needed, for example when filling car tires or a large paddling pool or swimming pool, the work will be much faster if a large amount of compressed air is available in the boiler
- the larger the boiler, the more air can be consumed without the engine having to restart. In this way, the engine is spared and the device has a longer life
- Noise pollution is significantly lower due to the less frequent engine start
But which boiler volume should you choose? You will already suspect it, because of course, the intended purpose of the compressor is of course again crucial. A small compressor with a boiler volume of 6 to 20 liters is quite suitable, if, for example, car tires, bicycle tires, balls, air mattresses or small paddling pools should be filled. On the other hand, if compressed air tools are to be operated which require a high output power, a compressor with a correspondingly large boiler volume should be selected.
The volume of the compressor
Also, the volume is an important point in choosing the right compressor. The engine of a compressor can be very noisy, which often makes it impossible to use the device indoors. High levels of noise from the compressor can also permanently damage your hearing and your neighbors may also feel bothered by the device.
The operating volume should therefore always be considered when buying. Often, the so-called sound pressure level in compressors is about 90 to 100 decibels. This roughly corresponds to the volume of a circular saw, a chainsaw or a chamber concert. If a compressor is regularly used with such a sound pressure level, a suitable ear protection should be worn in any case, because noise can have a negative effect on the health.
While the operation of noisy machinery and tools on a construction site or in the environment of a workshop is usually perceived as normal, however, the neighbors in the garden, on the campsite or in the rented apartment will rather not welcome if such a noisy device, the even exceeds the volume of a petrol lawnmower, is operated regularly. Wherever a quiet compressor is to be used, you can, therefore, fall back on a whisper compressor. These compressors are equipped with a special technology and work much quieter than their noisy relatives. The quietest compressors with whisper technology bring it only to a sound pressure level of about 45 decibels, while other quiet compressors produce a sound pressure level of about 50 to 70 decibels.TV, which is running at room volume and beats at about 60 decibels.
What should be the maximum pressure of the compressor?
The compressor compresses the air and thus creates a certain pressure. This pressure is measured in the bar and can be read on most instruments via a pressure gauge. How high the maximum pressure of the compressor should be, in turn, depends on how the device is to be used. For example, different air tools need different pressures to work properly. Important for the maximum pressure is that the regularly required working pressure is below this maximum pressure, otherwise, the compressor can be overloaded quickly if it always has to work in maximum operation. As a rule, the pressures of a compressor for the private sector are between 6 and 10 bar.
You must pay attention to this when buying a compressor
The variety of offers on the market can easily lose the overview if you want to buy a compressed air compressor. If you need a compressor with pressure vessel or without, the compressor must have 10 bar maximum pressure or less, what role do volume and weight play and for which compressor should one decide now? In our guide on gmomf.org, you will find a lot of information about the compressor and the most important purchase criteria we have summarized here again clearly for you.