piston vs screw compressors

Piston versus rotary screw compressors

A short comparison for the collision industry

Piston compressors are still the most common type of compressor found in the automotive service industry that includes gas stations, general service, quick lube shops, tire stores, fleet maintenance facilities, dealer fixed operations, and collision repair. For most of these facilities, the relatively low air demand and quality needed make the piston a cost effective choice. Collision repair shops, however, typically use much more compressed air and have higher air quality needs than other automotive service businesses. In these respects, collision repair is similar to manufacturing. In fact, many modern body shops might be more accurately referred to as automotive re-manufacturers.

These days, many body shop owners are finding out they have similar compressed air needs to larger industrial facilities and that rotary compressors offer significant operational benefits. Rotary compressors provide an extremely reliable supply of clean, dry compressed air. This may not be as critical for general repair, but collision repair stands apart because the end product is directly affected by air quality. When deciding between rotary and piston compressors, it is important to consider duty cycle and performance, energy efficiency, air quality, maintenance, and installation costs. The table below gives an at-a-glance comparison between these two types of compressors.

Rotary compressors Piston compressors
Duty cycle: 100% Limited
Oil carry-over 1 - 7 ppm 10 ppm - no upper limit
Noise levels 65 - 75 dB(A) 80+ dB(A)
Flow 4 - 4.5 cfm/hp 3 - 3.5 cfm/hp
Internal operating temp: 170°F - 200°F 300°F - 400°F
Discharge temp 15°F - 25°F above ambient 100♠F and higher above ambient

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