First, we ought to consider the exhaust pressure and the quantity of the exhaust.
According to the national regular, the exhaust pressure of general purpose air compressor is 0.7 MPa (7 atmospheric pressure) and the old regular is 0.8 MPa (8 atmospheric pressure). As the design working pressure of pneumatic tools and wind machinery is normally 0.4 Mpa, the working pressure of air compressor can fully meet up with the requirements. If the air compressor utilized by the consumer is bigger than 0.8MPa, it must be specially manufactured. The technique of forced pressurization can not be adopted in order to avoid accidents.
How big is the exhaust can be one of the primary parameters of the air compressor. Choosing the surroundings volume of the air flow compressor should match its exhaust volume and leave a 10% margin. If the air flow volume is huge and the surroundings compressor exhaust quantity is small, when the pneumatic tools start, the exhaust pressure of the air flow compressor will be greatly reduced, but the pneumatic tools can’t be driven. Of course, additionally it is wrong to pursue huge exhaust capacity blindly, since the larger the exhaust capacity, the larger the engine allocated by the air compressor, not merely the higher the purchase price, but also a waste materials of buying funds, and the usage of electricity and energy will become wasted.
Consider the combination of gas fields and conditions.
If the use of air space 
is narrow, it must be vertical; if there is a long-distance switch in the use of air (a lot more than 500 m), mobile type should be considered; if the use of electricity can’t be used, diesel engine driving type should be selected; if there is no circulating drinking water in the use of occasions, air-cooled type should be chosen. In the air-cooled and water-cooled cooling settings, many users have an incorrect proven fact that water-cooled is good, but in fact it isn’t. The air-cooled type makes up about a lot more than 90% of the tiny Chain compressors at home and abroad. This is since the air-cooled type is easy in design no water source is needed in use. There are four fatal shortcomings of water-cooled compressor: it will need to have a complete higher and lower water system with large expenditure; water-cooled cooler has brief life; it is easy to freeze the cylinder in wintertime in the north; it will waste a whole lot of water in regular operation.
After that consider the compressed quality of air.
Generally, compressed air produced by air compressor contains a certain amount of lubricating oil and water. In some cases, it is prohibited from oil and water. At the moment, attention ought to be paid not merely to selecting compressor, but also to the addition of auxiliary devices when necessary.
Lastly, it is to expand the knowledge of reference.
1. Balance: With the solid rise of China’s overall economy and the continuous emancipation of the minds of all sorts of manufacturers, manufacturers from coast to coast are busy with creation work. In the process of production, atmosphere compressors, which play an important role, are often fully loaded and operate all-weather. In the entire production of factories, surroundings compressor gas production is unstable, which is an extremely troublesome thing, often will bring incalculable losses. Therefore, whenever we purchase air compressors, the 1st criterion may be the stability of air flow compressors. 
At the moment, some high-end brands both in the home and overseas can meet this necessity. With the mature technology of variable frequency atmosphere compressor, it could be said to meet this requirement.
2. Gas creation: The second is gas creation. Some enterprises possess very good quality of gas. For instance, in the pharmaceutical industry, basically the gas they need is oil-free of charge. In this regard, it is still based on the enterprise’s very own situation. If the business has a high demand for this, then it has been a long period to buy more well-known devices. If the demand isn’t high, it depends upon other conditions. As the near future development craze of the air compressor industry, the adjustable frequency air compressor continues to be very exceptional in gas production, since the variable frequency atmosphere compressor includes a prominent characteristic of tracking gas creation, and at exactly the same time the gas quality produced is very considerable.
3. Power consumption: That is a comparatively important place as well as the focus of debate, because atmosphere compressor, as a simple equipment, is generally operated all-weather, and surroundings compressor itself is an extremely power-consuming equipment, the overall manufacturer of atmosphere compressor power consumption accounts for 20-30% of the total plant power usage. If effective control, the result is very obvious. Many domestic enterprises are actually pursuing the base price. In fact, underneath price is rather one-sided. For general creation enterprises, the price of atmosphere compressor only makes up about 5% of the full total cost of air flow compressor, 9% of the maintenance and labor costs, and 86% of the total cost of electricity. Therefore, considering the final expenditure, the frequency conversion air compressor should be much lower compared to the ordinary surroundings compressor. Frequency conversion air flow compressor is only the first expense, but invest the the electricity price into account, you can really calculate a bill. Today, the general energy-saving amount of frequency converter atmosphere compressor is quite objective, and the domestic professional rate of recurrence converter air compressor, its power-saving rate is as high as 30%, usually within a calendar year can recover the difference. Therefore, when choosing surroundings compressor, choosing an excellent variable frequency surroundings compressor is really the best alternative to the issue of power consumption.