If you’re considering purchasing a new air compressor, you’ll need to understand the differences between reciprocating air compressors and rotary air compressors, and the applications they’re best suited for.
What Is a Reciprocating Air Compressor?
A reciprocating air compressor uses pistons driven by a crankshaft to compress the air. They’re efficient, low-maintenance, and perform well for applications that require small and sporadic amounts of compressed air.
What Is a Rotary Screw Air Compressor?
Rotary screw air compressors use two helical screws, or rotors, to compress air. As the interlocking spirals turn, the air is forced through the chambers and compressed into a smaller space. The air is continuously compressed as the rotors turn. They’re designed for applications that require large and continuous amounts of compressed air.
A Side by Side Comparison
There are three main factors to consider when choosing between rotary and reciprocating—Application, Amount and Environment. Below we’ve provided the pros and cons of each type of com pressor.
Reciprocating Compressor
Pros:
- Low initial capital investment (20-50% less than rotary)
- Simple maintenance
- Can be run in sheltered outdoor or dirty indoor environments
- Better energy efficiency for low CFM, intermittent applications
Rotary Screw Compressor
Pros:
- Higher CFM per HP
- Cleaner air (less oil carryover, typically 3-8 ppm)
- Better energy efficiency for high CFM, continuous applications
- Longer life (lower total cost of ownership over time)
- Cooler internal operating temperature (80-99°F)
- Quiet operation
High reliability
Cons:
- Noisy (up to 100 dB)
- Hot (internal operating temperature 150-200°F)
- High oil carryover (10-50 ppm)
- Lower life expectancy
- Lower reliability and uptime
Cons:
- Higher CFM per HP
- Cleaner air (less oil carryover, typically 3-8 ppm)
- Better energy efficiency for high CFM, continuous applications
- Longer life (lower total cost of ownership over time)
- Cooler internal operating temperature (80-99°F)
- Quiet operation
High reliability
Uses:
- Intermittent use (non-continuous)
- Lower CFM
- Manual applications
- Smaller facilities
Uses:
- Continuous use
- Higher CFM
- High-volume manufacturing
- Applications requiring clean air
When to Use a Reciprocating Air Compressor
Reciprocating air compressors are best for applications that require intermittent air such as machine shops, construction sites, and small-scale manufacturing.
Another consideration is the future growth of a business. It may be advantageous to purchase a larger compressor ( up to 50% larger) that can scale with the business. Another advantage of a larger compressor is proper cycling which reduces heat and wear and tear on the motor.
When to Use a Rotary Air Compressor
Rotary air compressors are best for applications that require consistent air such as large-scale manufacturing and conveyor systems. They are designed to operate nonstop and produce a strong and consistent flow of air. Because the air produced by rotary air compressors is much cleaner than air produced by reciprocating compressors, they are the best choice for paint lines, food processing and packaging, and other applications where clean, dry air is essential.
Fixed speed rotary screw compressors are not designed for intermittent use and may experience performance issues if they are not used close to their full capacity. If your compressed air demand varies, but you want the advantages of a rotary screw machine, you may want to consider a variable speed drive (VSD) compressor. While a fixed-speed compressor is always operating at the same RPM, a VSD motor can ramp up or down depending on demand.
