An air compressor is a mechanical device that increases the pressure of a gas by reducing its volume. An air compressor is a specific type of gas compressor. There are two types of compressors: volumetric compressors and centrifugal compressors (also call dynamic compressors).

Air compressors are use in all manufacturing processes and industrial applications that require compress air.

  • How to choose an industrial air compressor?

    KAESER air compressorKAESER air compressor

    The first step in choosing your air compressor is to determine how often it will be use base on the compress air needs of your application.

    You also have to determine whether it should be mobile or permanently install. In this case, you need to make sure that the compressor is well ventilate for optimal cooling.

    Another important element to consider is the continuous operating time of your compressor. The manufacturers usually specify a duty cycle for their products. It determines how long the compressor can be operate within an hour. A compressor with a duty cycle of 30% can only run for 18 minutes and then has to cool for 42 minutes.

    Air compressors enable the use of various portable pneumatic tools:  hammers,  nailers ,  air tools ,  pneumatic drills , pneumatic guns,  dye jet ,  sand blasting equipment , etc.

    Stationary or mobile air compressors can also be use in industry or agriculture, for example:

      • For compress air tools in production lines
      • blow molding bottles or gas containers
      •  air supply in pneumatic cylinders
      • sandblasting metal parts
      • spraying cultures
      • ventilation of greenhouses, etc.


  • What is the recommend size for your compressor?

    BOGE air compressor
    BOGE air compressor

    To determine the size of your compressor, you first need to know the maximum pressure you will need. It is define by the properties of the equipment or the compress air circuit (industrial or agricultural) from which the compressor is supply. It can be express in  pounds per square inch (psi), bar, or pascal (Pa). Depending on the pressure, you need a single-stage (maximum 135 psi or 9 bar) or a multi-stage compressor, with the latter significantly increasing the pressure (maximum 5,800 psi or 400 bar).

    You should also know the maximum amount of throughput you will need. The volume flow represents the amount of air available for supplying the various devices that have to be connect  to one another on the compressor. It can be express in cubic feet per minute ( cfm), liters per second (l / s), or cubic meters per hour (m3 / h). Without oversizing the compressor, it is better to plan a safety margin of approx. 30% of the estimate requirement in order to avoid unpleasant surprises.

    The performance of the compressor depends on the require air volume and the outlet pressure . If a compressor is design with a high nominal output but a low flow rate, it is intend for occasional use and its cooling requires long pauses.

    Compressors usually have a compress air tank that enables the motor to be start according to the compress air requirement. You need to calibrate this tank correctly so that it doesn’t put a constant load on the engine. Some compressors are available with a vertical tank , which reduces their footprint when installing in tight spaces.

  • Choosing a compressor

    INGERSOLL RAND brand air compressor
    INGERSOLL RAND brand air compressor

    Most compressors are positive displacement: a mechanism reduces the volume of air to compress it. These compressors are usually driven by electric motors.

      • Reciprocating compressors

        These compressors can be single cylinder. The pressure of this type of compressor can rise to 10 bar . The same type of compressor can also be multi-stage: the pressure is increase in stages and can reach up to 400 bar . You can choose this type of compressor if you are looking for an intermittent function: the duty cycle is a maximum of 60%, i.e. it can only work 35 minutes per hour work. The compres air reserve must be sufficient in relation to the estimate volume flow so that the compressor does not have to be operate more often. Another potential problem with this type of compressor is that it also expels oil with the compress air. If the air you need needs to be clean, you need to provide a filter system or choose an oil-free compressor (this is the case, for example, in the electronics, pharmaceutical, food or clean room industries). In addition, reciprocating compressors are relatively noisy, which is a nuisance for people working in the vicinity.



      • Screw compressors

        It is the most common model use in industry. It uses augers instead of the piston. The pressure obtain can vary from 5 bar for a single cylinder model to 13 bar for a multi-stage model, this type of compressor generally offers a high flow rate and high compression ratio with a single stage, which allows manufacturers to offer compressors with reduce dimensions, in contrast to with a similar piston model (which should be multi-stage to provide the same pressure).

    The screw compressor can have a duty cycle of 100% and can therefore be operate continuously. Some screw compressors are speed-control. You can adapt your speed to the respective compress air requirement and thus optimize your energy requirement.



      • Rotary compressor

      • Here pallets (plates) slide in an eccentric rotor and cause the air to be compress. The energy efficiency of these compressors is generally attractive. With the same pressure and the same flow rates, these compressors have a lower speed than screw compressors, which reduces the wear and tear of the parts and the maintenance effort and thus increases the service life. They are use in various fields of activity such as the printing, wood and packaging industries. In industries that require clean air, such as energy or medicine, many models are available without oil.



      • Centrifugal compressor

        In these compressors, the air is suck through the machine by means of a paddle wheel; the principle is the same as that of the turbocharger in the automotive industry. They are generally use when continuous high flow at high pressure is require, which is particularly the case in energy production and in the chemical industry. These compressors are usually equip with an integrate reducer to regulate flow and pressure at optimal speed. These compressors are generally equip with a gear reducer to allow the engine to operate at optimum speed. You can achieve a throughput of up to 500,000 m3 / h with a pressure of 200 bars .


    Compressors are divide into three main groups:

      • Stationary  compressors  These are permanently install machines. They are generally very powerful, offering both high flow and high pressure.


      • Mobile or semi-stationary compressors       They usually have similar properties to stationary Monoblock compressors, but can be relocate to different areas (e.g. construction sites). Their base is generally designe for the forks of a forklift truck to pass through. These compressors are generally equip with an internal combustion engine.


      • Portable compressors.  In general, they are not intend for intensive use, but have the advantage that they are very easy to move.


  • In which cases is an oil-free compressor suitable?

    Some compressors are available without oil , so the air they expel is clean. They are therefore environmentally friendly and less harmful. They are primarily use in the electronics industry, including semiconductor manufacturing, pharmaceuticals, chemistry, medicine, automobile assembly or finishing, and food processing.

    If you have to choose an oil – free compressor, make sure that it complies with ISO standard class 8573-1, as this is the only class that guarantees complete oil – free use. The upper classes determine the maximum amount of oil in the compress air, which usually requires the use of an air dryer. These compressors, which do not offer very high pressure values, are usually not design for intensive use.

    In a reciprocating compressor, the lubrication can be replace by a Teflon or silicone coating that protects moving parts. This can also be replace by inject water or water circulating in a close circuit. The noise generate by these compressors is often louder, but they require less maintenance.

    Main applications of oil-free compressors:

      • Electronics industry


      • Chemical industry


      • Pharmaceutical industry


      • Medical industry


      • Agriculture and Food Industry


  • Which motors are use for compressors?

    The most economical compressors with electric motors equip, but are also powerful the least, especially when supply with single-phase power warden. Industrad Group market also offers compressors, internal combustion engines diesel  or gasoline ) are driven. Compressors equip with an internal combustion engine are generally intend for outdoor use because of their exhaust gases.

  • What does an air compressor cost?

    The prices below are for the general public; the cheapest compressors do not have an air tank.

      • Piston compressor: from € 70 to € 11,000
      • Screw compressor: from € 200 to € 16,000
      • Oil-free compressor: from 70 €
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