Any advice on rotary screw compressors?

Expert Tips for Rotary Screw Compressors

5 HP Rotary Screw Compressor with 80 Gallon Tank

This powerful 5 HP Rotary Screw Air Compressor featuring an 80 Gallon Tank is designed to handle your toughest tasks. Enjoy peace of mind with a 10 Year Warranty.

Check now

Quiet 7.5 HP Air Compressor, Single Phase, 80 Gallon Tank, Vertical Design

Eaton Compressor offers a robust selection of quiet air compressors, highlighted by this efficient single phase 7.5 HP model, topped with an 80 Gallon Tank.

NEW 7.5 HP 2 Stage 1 Phase 80 Gallon Vertical Champion Air Compressor with AFTER COOLER

We are currently dealing with a global parts shortage affecting delivery times for many air compressor models. Despite temporarily taking these units offline, we can still place orders for you. For real-time updates about the specific unit you’re interested in, please reach out to us directly...

Many rotary screw compressors operate on a 3-phase system, and some models, like those from Kaeser, require a well-balanced three-phase supply. These compressors are tailored for continuous air demand; using them under low-load conditions can lead to issues. Piston compressors, in contrast, generate sound primarily due to the motor/air pump speed and air intake noise. If considering piston options, the Eaton piston compressor Emax (Polar Air) in the 7.5 HP range is noteworthy for its low-speed motor and cast-iron V4 compressor design, delivering high air output with rapid recovery times. If your focus is noise reduction, consider a sound enclosure or closet, but ensure adequate ventilation for heat dissipation. Eaton does offer a 5 HP single-phase rotary compressor, albeit at a significantly higher price. If feasible, incorporating an after cooler is advisable to eliminate moisture before it enters the tank, along with an automatic drain feature. Eaton’s compressors boast warranties up to 5 years, although their piston models are rated for about 70% continuous use, suitable for light industrial applications. For quiet piston compressors, California Air offers a line, but these are better suited for light-duty tasks and are oil-less, limiting their lifespan. I recommend opting for a slower-turning piston compressor equipped with mufflers and possibly a noise attenuation enclosure. Always consider user reviews for guidance.

Comparison Between Piston and Screw Compressors

Establishing a compressed air system can be intricate. Key considerations include pipe size, number and positioning of air drops, compressor placement, and appropriate brands for accessories such as oil filters, hoses, and gauges.

One of the initial and crucial decisions in designing such systems is selecting between piston compressors and screw compressors. Each type has its strengths; understanding their costs, performance, and maintenance requirements is essential for making an informed choice.

Piston or Reciprocating Air Compressors

Piston compressors function by moving pistons driven by a crankshaft within a cylinder, drawing air into the compressor during the downward motion and pushing it into the tank while compressing it during the upward motion.

Screw Air Compressors

These compressors utilize spiral screws situated within a shaft to compress air. They employ two helical screws (male and female) that do not touch, facilitating airflow into the tank through a positive displacement method. The working mechanisms of these machines can be intricate, but this provides a basic insight into piston versus screw compressors.

Key Considerations When Choosing a Compressor

Here are a few significant aspects to keep in mind when choosing between piston or screw air compressors.

Link to Comair

Initial and Long-Term Costs

Piston compressors typically boast a lower initial cost. While prices can vary, piston models generally cost less upfront compared to screw compressors. However, the long-term costs can be higher with piston compressors, which usually require more energy and maintenance over time.

Service and Maintenance

The initial investment for screw compressors is higher due to fewer moving parts, resulting in potentially lower maintenance requirements compared to piston compressors. This leads to decreased overhead costs associated with repairs and interruptions in productivity.

Noise Levels

Piston compressors are notorious for generating excessive noise, which can translate to higher costs in hearing protection and potential regulatory issues. In a test by Kaeser, a 5 HP piston compressor recorded sound levels of 83 dB-A, significantly louder than a comparable screw compressor at 68 dB-A. Thus, the quieter operation of screw compressors may lead to better working conditions.

Space Requirements

Due to their duty cycle limitations, piston compressors generally require larger storage tanks, consuming more space. In contrast, screw compressors can be compact, offering a more efficient use of space.

Conclusion: Large Operations Favor Screw Compressors

While there are additional factors to consider (feel free to reach out with questions), the points discussed are pivotal in guiding your decision. Piston compressors are a cost-effective choice for smaller operations with limited air compression needs, whereas screw compressors are ideal for larger-scale applications, delivering consistent airflow and lower long-term costs.

We offer an extensive range of both piston and screw compressors. Connect with our team for recommendations tailored to your compressed air system needs.

If you wish to dive deeper, visit our page on the High Pressure Screw Air Compressor.