The two most common mobile compressors are rotary screw air compressors and reciprocating (or piston) air compressors. But what’s the difference between them? In this article, we’ll compare the performance of rotary screw vs. reciprocating air compressors and help you choose the best solution for your work vehicle.
Reciprocating air compressors, which are also called “piston” or “recip” air compressors, are widely used throughout various service industries due to their price and availability. Many commercial vehicle operators request reciprocating air compressors because they simply do not understand the difference between a rotary screw and a reciprocating air compressor and are only familiar with what they’ve traditionally used.
But reciprocating air compressors are not the only option. Rotary screw air compressors provide better performance and often require less space, which makes them an attractive alternate option. The image below shows two gas powered air compressors, with a reciprocating air compressor on the left and a rotary screw air compressor on the right:
Key Advantages of Rotary Screw Air Compressors
Rotary screws have very distinct and important advantages over reciprocating air compressors:
- Work faster. Generally, rotary screw air compressors deliver more air compared to reciprocating compressors of the same size. Reciprocating compressors require air reservoir tanks to handle larger air demands and reduce air pulses created in the compression process. Rotary screw compressors do not create the same type of air pulses and can deliver large amounts of air when required without the need of a reservoir tank. You won’t have to wait for your compressor to keep up with your work, which means you can get jobs faster and complete more jobs in a day!
- Work longer. Rotary screw air compressors operate at 100% duty cycle. Duty cycle is the amount of time a compressor can continuously operate without stopping to prevent overheating in a given time. For example, if a compressor can run for 60 minutes in a 60-minute period without stopping, it is 100% duty cycle. If it can only run for 30 out of 60 minutes, it is 50% duty cycle. Most reciprocating compressors are only capable of 50% duty cycle. This means those compressors can only operate half the time which reduces your ability to get the job done. A rotary screw compressor is designed to run 100% of the time so you can get your job done without interruption.
- Work worry-free. Rotary screw air compressors last longer than reciprocating air compressors. Like an engine, reciprocating compressors have piston rings and other components that contact each other and wear over time. With that wear comes a decrease in performance, oil carryover and more heat generation. A rotary screw compressor is designed so that the compressor oil seals the internal rotors, preventing parts from wearing out. Unlike a reciprocating compressor that loses performance with age, the rotary screw compressor maintains the same performance throughout its long life.
- Work with more. Rotary screw air compressors are lighter weight and provide more capacity in a smaller package than reciprocating air compressors. This means vehicles can haul more equipment, tools, and materials, and can spend less time driving between shops and job sites. Not only can you haul more, but you can also do more. The rotary screw compressor will provide enough power to operate the most common hand-held pneumatic tools. From impact wrenches and deburring tools to grinders, you’ll get the air to power these tools when you need it.
Comparing Rotary Screw vs. Reciprocating Air Compressors
The following charts allow you to compare the benefits and disadvantages of both rotary screw and reciprocating air compressors.
|Continuous air flow||Inexpensive|
|100% Duty Cycle||Simple maintenance|
|Long lifespan||Capable of high pressures|
|Better energy efficiency|
|Large quantities of air|
|Higher CFM per hp|
|Air receiver tank is not required|
*VMAC’s rotary screw air compressors include a VMAC Limited Lifetime Warranty.
|More expensive upfront||Interrupted flow rates|
|Requires skilled maintenance for rebuilds||20% to 30% duty cycle|
|Low life expectancy|
|Requires air receiver tank|
Why People Prefer Rotary Screw Air Compressors
VMAC surveyed 340 professionals who use mobile air for the 2022 State of the Mobile Compressed Air Industry Report and discovered that 80% of people prefer rotary screw air compressors over reciprocating. The same result was also reported in 2021.
When asked why they prefer rotary screw air compressors, industry professionals said it was because of performance, quality/reliability, and size/weight. Meanwhile, the 20% who preferred reciprocating air compressors choose that option because of ease of service and repair, price, and availability.
Ultimately, if your primary concern is size and weight or job performance from a high-quality system that will last a vehicle’s lifetime, rotary screw air compressors are the way to go. By contrast, if upfront price, ease of repair, and widespread availability are your driving motivators, a reciprocating air compressor may be a better fit for your needs.
Learn More About Rotary Screw Air Compressors
Rotary screw compressors provide many advantages over their reciprocating compressor counterparts. Size, air delivery, duty cycle and longevity are all factors that firmly land in favor of a rotary screw compressor. Learn more in our Guide to Rotary Screw Air Compressors.