Rotary Compressor vs. Reciprocating Compressor – Which is the Best?

The most prevalent form of compressors today is the positive displacement air compressor, which is divided into two types: rotary air compressors and reciprocating compressors. 

The first difference is in the way they operate. Rotary compressors use two screws that revolve in opposite directions to compress the air between them. A reciprocating compressor consists of a piston-cylinder mechanism that fills with gases and compresses them as the piston moves.

Delivery pressure, compressor speed, air supply, balancing, compressor size, and lubrication are all features that differ between rotary and reciprocating compressors.

In this guide, we will go toe to toe between the rotary compressor vs reciprocating compressor and see which one is better than the other.

What Is a Rotary Compressor?

cross section of a rotary pump

A rotary compressor uses rotating blades or an eccentric roller attached to the motor to produce compressed fluid or refrigerant. The air is driven through the chambers and squeezed into a smaller area as the interlocking spirals revolve. Air is compressed as the rotors move in this operation.

They are ideal for applications that need constant operation. Rotary compressors are used in large industrial applications, sandblasting, and jackhammers.

How Does a Rotary Compressor Work?

Rotary screw compressors compress air through rotary movements. A set of rotors is located within the compressor. When they are twisted in unison, the air is trapped between them. The rotors can work without touching to maintain compression.

These compressors can operate at high shaft speeds with no mechanical or volumetric losses that might lead to unbalance. Screw technology may therefore work with a high flow rate with a small, compact design.

What Is a Reciprocating Compressor?

A orange reciprocating pump

A reciprocating air compressor is a positive displacement air compressor that draws air into a chamber and compresses it with the aid of a reciprocating piston.

A reciprocating air compressor compresses air using pistons powered by a crankshaft. They compress CNG and many industrial and chemical applications, such as gas lift in oil wells.

How Does the Reciprocating Compressor Work?

A reciprocating compressor follows these few basic steps:

  • A diesel engine is generally used to power reciprocating compressors.
  • This can be accomplished by a belt-drive system which will run if the engine is turned on.
  • A device for unloading aids the entire cycle, and some systems feature a governor that is generally placed to the compressor.
  • In the presence of a governor, intake and output pressures are well regulated.

What Are the Advantages of Rotary Compressor Over Reciprocating Compressor?

There are several advantages of a rotary compressor compared to a reciprocating one:

100% Duty Cycle

Rotary screw air compressors have a duty cycle of 100%. The duty cycle of a compressor is the length of time it can run without pausing in a certain period. 

Most reciprocating compressors can only operate at a half-duty. This implies that the compressors can only run for half the time, limiting your capacity to complete the operation. A rotary compressor is designed to run continuously, allowing you to complete your task without interruption. It’s easy, reliable, and efficient at handling its tasks effortlessly.

Energy Efficiency

When choosing an air compressor, energy efficiency is likely the most crucial element. You want a system that can supply more air while using less energy, and rotary ran machines can accomplish that. 

Because there are fewer movable components in a rotary compressor, it has better mechanical efficiency. Rotary compressors may attain mechanical efficiency of up to 90%, which reciprocating compressors couldn’t match. 

For high CFM and continuous applications, it offers higher energy efficiency.

Lighter Weight

For the same amount of power, the rotary compressor is smaller than the reciprocating compressor. This means trucks can transport more equipment, tools, and materials while traveling between job sites and shops.

Life Cycle

Air compressors with rotary screw blades survive longer than reciprocating air compressors. Rotating machines frequently exceed their already outstanding design lifespan. 

Piston rings and other components in reciprocating compressors rub against each other and wear out over time. Wear causes a reduction in performance and increased heat generation. 

Easy engineering, reduced working speeds, and low friction are just a few of the advantages that rotary has over reciprocating.

What Is the Main Advantage of a Rotary Compressor?

A rotary compressor is cost-effective, energy-efficient, and has a great life span; however, the area where it shines the most is its work speed.

Faster Work Speeds

To accommodate higher air needs and decrease air pulses formed during the compression process, reciprocating compressors require air reservoir tanks. While the rotary counterparts don’t require a reservoir to generate large amounts of air. This means easy compatibility with your workflow and reduced time wastage to carry on the hard work. 

Energy efficiency and lifespans are a great way to judge a compressor. But when it comes to overcoming time limitations, the rotary compressor has your back.

Disadvantages of Rotary Compressor

No matter how good a device is, there are a few clear disadvantages to be discussed and kept in mind before choosing which one is better. However, the rotary compressor is an excellent device that has little to no disadvantages – putting it right on top.

  • When compared to a reciprocating compressor, the discharge pressure per stage is minimal.
  • There is no capacity or compression ratio flexibility.
  • Initial capital investment is high.
  • Regular expert maintenance is required.
  • A clean operational environment is required.

Advantages and Disadvantages of the Reciprocating Compressor

Following are a few pros and cons of reciprocating compressors and how they can affect your experience with the machine.

Advantages

  • Produces a lot of power and pressure.
  • Initial setup costs are lower.
  • Low CFM, intermittent applications benefit from improved energy efficiency.
  • Manual applications and smaller shops.
  • Easy maintenance

Disadvantages

  • Flow rates are not constant. 
  • Life expectancy is low.
  • Extreme heat.
  • The heat generated by piston friction requires cooling time.
  • Not intended to be used all the time.
  • Oil carryover is high.

Why Do People Prefer Rotary Air Compressors? 

It has been quite clear why people looking for a compressor might be interested in the rotary air compressors over their dull counterparts. A survey conducted by the VMAC showed that over 80% of 350 professionals recommended rotary air compressors.

And many of these professionals showed interest in rotary air compressors because of their ease of service, maintenance, and efficiency of energy.

This shows just how much trust many professionals have in rotary compressors and their widespread performance. 

Since rotary air compressors are lightweight and take up less space than desired, their use and ultimate customer satisfaction continue to increase. 

When Should a Rotary Screw Air Compressor Be Used? 

Rotary air compressors are ideal for applications requiring constant airflow. Because rotary air compressors create cleaner air than reciprocating air compressors, they are also the ideal choice for plant-based industries as well as other applications requiring clean air.

Rotary Screw Air Compressors work best at pressures less than 150 psi. Because they are durable and have lengthy lifecycles, they are a more cost-effective solution for many medical and industrial establishments.

Rotary compressors are not made for intermittent usage, and if not operated to their maximum capacity, you may encounter performance concerns.

FAQs

Is a rotary compressor better or reciprocating?

Compared to reciprocating compressors, rotary compressors offer a clear advantage from an energy efficiency standpoint. There are several advantages to choosing the rotary compressor. Rotary compressors are able to perform at their best due to their 100% duty cycle, energy efficiency, lighter weight, and long lifespan.

In comparison with reciprocating compressors, what are the advantages of rotary compressors?

Rotary compressors have several advantages. Because of their high efficiency, lightweight, and faster work speeds, rotary compressors are always able to perform at their best.

How does a rotary compressor work?

Rotating screws compress air through rotary movements. The compressor has a set of rotors. The air is trapped between them when they are twisted together. Compression is maintained without the rotors touching.

Rotary Compressor vs Reciprocating Compressor: Final Thoughts

The rotary compressor has a clear upper hand over its counterpart. From energy efficiency to life expectancy, the rotary compressors have a clear margin over the reciprocating compressors.

The 100% Duty Cycle, energy efficiency, lighter weight, and lifecycle are those few elements that help bring out the best in the rotary compressors. 

Rotating compressors are superior to reciprocating compressors in every way. The initial investment is worth its weight in gold in terms of lifetime operational expenditure reductions.

If you found this article helpful, you may also like: Air Compressor Buying Guide: All You Need to Know Before Making a Purchase.