First, we ought to consider the exhaust pressure and the quantity of the exhaust.
Based on the national regular, the exhaust pressure of general purpose surroundings compressor is 0.7 MPa (7 atmospheric pressure) and the old standard is 0.8 MPa (8 atmospheric pressure). As the design operating pressure of pneumatic equipment and wind machinery is usually 0.4 Mpa, the functioning pressure of surroundings compressor can fully meet the requirements. If the surroundings compressor utilized by the user is larger than 0.8MPa, it must be specially manufactured. The method of forced pressurization can’t be Water-lubricated Air Compressor adopted in order to avoid accidents.
The size of the exhaust is also one of the main parameters of the air compressor. Choosing the air volume of the air flow compressor should match its own exhaust volume and leave a 
10% margin. If the surroundings volume is large and the surroundings compressor exhaust volume is little, when the pneumatic tools begin, the exhaust pressure of the air flow compressor will be greatly reduced, but the pneumatic tools can not be driven. Of course, additionally it is wrong to pursue huge exhaust capacity blindly, because the larger the exhaust capacity, the larger the engine allocated by the surroundings compressor, not merely the higher the price, but also a waste of purchasing funds, and the use of energy and energy will end up being wasted.
Consider the mixture of gas fields and conditions.
If the use of air space is narrow, it should be vertical; if there is a long-distance change in the use of air (a lot more than 500 m), mobile type should be considered; if the utilization of electricity can’t be utilized, diesel engine driving type should be selected; if there is simply no circulating water in the use of occasions, air-cooled type ought to be selected. In the air-cooled and water-cooled cooling modes, many users have an incorrect idea that water-cooled is good, but in fact it isn’t. The air-cooled type accounts for more than 90% of the small compressors at home and abroad. That is since the air-cooled type is simple in design no water source is necessary in use. There are four fatal shortcomings of water-cooled compressor: it will need to have a complete upper and lower water program with large investment; water-cooled cooler has short life; it is easy to freeze the cylinder in winter in the north; it’ll waste a lot of water in normal operation.
After that consider the compressed air quality.
Generally, compressed air made by air compressor contains a specific quantity of lubricating oil and water. In some instances, it is prohibited from oil and water. At the moment, attention ought to be paid not merely to the selection of compressor, but also to the addition of auxiliary gadgets when necessary.
Lastly, it is to expand the data of reference.
1. Stability: With the solid rise of China’s overall economy and the constant emancipation of the thoughts of all kinds of manufacturers, manufacturers all over the country are busy with production work. In the process of production, air flow compressors, which play an important role, are often fully loaded and operate all-weather. In the full production of factories, surroundings compressor gas production is usually unstable, which is an extremely troublesome thing, often will bring incalculable losses. Therefore, when we purchase air flow compressors, the first 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 requirement. With the mature technology of adjustable frequency air flow compressor, it can be thought to meet this requirement.
2. Gas creation: The second is gas production. Some enterprises have very good quality of gas. For example, in the pharmaceutical sector, basically the gas they want is oil-free. In this regard, it is still based on the enterprise’s own situation. If the enterprise includes a high demand for this, then it has been a long time to buy more well-known devices. If the demand is not high, it depends on other situations. As the future development development of the air compressor industry, the variable frequency air compressor continues to be very exceptional in gas production, since the variable frequency air compressor has a prominent characteristic of tracking gas creation, and at the same time the gas quality produced is very considerable.
3. Power consumption: That is a relatively important place and also the focus of debate, because atmosphere compressor, as a simple equipment, is generally managed all-weather, and atmosphere compressor itself is an extremely power-consuming equipment, the general manufacturer of air flow compressor power consumption accounts for 20-30% of the total plant power consumption. If effective control, the effect is very apparent. Many domestic enterprises are actually pursuing the bottom price. In fact, underneath price is rather one-sided. For general production enterprises, the purchase price of surroundings compressor only makes up about 5% of the full 
total cost of surroundings compressor, 9% of the maintenance and labor costs, and 86% of the full total cost of energy. Therefore, considering the last expenditure, the frequency conversion air compressor must be much lower compared to the ordinary atmosphere compressor. Frequency conversion air compressor is the first investment, but if you take the electricity price into account, you can really calculate a bill. Currently, the general energy-saving amount of rate of recurrence converter air compressor is quite objective, and the domestic professional regularity converter atmosphere compressor, its power-saving price is really as high as 30%, usually within a 12 months can recover the difference. Therefore, whenever choosing air compressor, choosing a good variable frequency air compressor is really the best remedy to the issue of power consumption.