总结而言，空压机选择的基本准则有三条，可靠性、安全性与经济性。   一、机器的使用环境和条件。在场地无供水，场地狭小的情况下，选择立式空压机;场地有长距离的变动(超过500米)，须考虑移动式空压机;场地不能供电，则必须选择风冷式。客户们经常错误的认为水冷式比较好，其实在国内外小型空压机中风冷式占百分之九十以上。原因是风冷式空压机在设计上更加简洁，无需水源。水冷式空压机必须具备完善的供水系统，投资大;水冷却器寿命较短;运行过程中大量浪费水资源;北方冬季易冻坏气缸。   二、所需压缩空气的质量。一般的空压机都含有一定的润滑油，且含有水分，在禁油禁水的场合不仅要注意空压机的选型，在必要的时候还要增加附属装置。此时可选择无油空压机。无油空压机基本不含油，但润滑不良，因此故障率高;此种空压机因含有聚四氟乙烯，食品及制药行业不能使用，无油空压机只能做到不含油，但无法做到不含水。也可在空压机后添加净化装置或干燥机，这种装置能够使空压机不含油和水分，使含油水量在5ppm以下。   三、空压机的排气压力及排气量。常用的空压机排气压力为0.7MPA，0.8MPA，目前社会上还有排气压力为0.5MPA的空压机，输气距离过近。这种空压机为一级压缩，压力比太大，易排气温度过高，造成气缸积炭，导致事故的发生。大于0.8MPA的空压机一般要特别制造，不可强行增压。空压机气量的选择要匹配所需的排气量(并留有百分之十的余量)，空压机最重要的参数之一就是排气量。   四、运行的可靠性。空压机运行时伴有升温和压力，运行的安全性是最重要的，现在国家对空压机的生产进行规范化的“两证”制度化管理，即空压机生产许可证和压力容器生产许可证。因此，在选择空压机时，一定要严格审查“两证”，通常具备完善的产品质量保证系统。
Analytical summary of the basic criteria for air compressor selection, there are three basic criteria for air compressor selection, reliability, safety and economy. 1. The working environment and conditions of the machine. In the case of no water supply and narrow site, vertical air compressor should be chosen; if the site has long-distance change (more than 500 meters), mobile air compressor should be considered; if the site can not supply electricity, air-cooled air compressor must be selected. Customers often mistakenly think that water-cooled type is better, in fact, air-cooled type accounts for more than 90% of small air compressors at home and abroad. The reason is that the air-cooled air compressor is more concise in design and does not need water source. Water-cooled air compressor must have perfect water supply system with large investment, short life of water cooler, a large amount of waste of water resources during operation, and easy to freeze cylinders in winter in North China. 2. The quality of compressed air required. General air compressors contain a certain amount of lubricating oil and water. In the case of oil prohibition and water prohibition, attention should be paid not only to the selection of air compressors, but also to the addition of ancillary devices when necessary. At this time, oil-free air compressor can be selected. Oil-free air compressor basically does not contain oil, but the lubrication is poor, so the failure rate is high; this kind of air compressor contains PTFE, food and pharmaceutical industry can not use, oil-free air compressor can only do without oil, but can not do without water. It is also possible to add a purifying device or a dryer after the air compressor, which can make the air compressor free of oil and water, so that the oil and water content is less than 5 ppm. 3. Exhaust Pressure and Exhaust Volume of Air Compressor. Commonly used air compressor exhaust pressure is 0.7 MPA, 0.8 MPA. At present, there are still air compressors with exhaust pressure of 0.5 MPA in society, and the distance of gas transmission is too close. This kind of air compressor is one-stage compression, the pressure ratio is too large, and the exhaust temperature is too high, resulting in carbon deposition in the cylinder, leading to accidents. Air compressors larger than 0.8MPA are usually specially manufactured and cannot be pressurized by force. The selection of air compressor volume should match the required exhaust volume (with a 10% margin). One of the most important parameters of air compressor is the exhaust volume. 4. Reliability of operation. Air compressor operation is accompanied by heating and pressure, the safety of operation is the most important. Now the state carries out standardized "two certificates" institutionalized management of the production of air compressor, that is, air compressor production license and pressure vessel production license. Therefore, when choosing air compressor, we must strictly examine the "two certificates", usually with a perfect product quality assurance system.