Rotary Screw Air Compressors
L Series 7 - 11 kW
Fixed & Regulated Speed
Well known in the industry for quality and reliability, CompAir continuously develops and expands the L-Series to achieve optimum performance and efficiency and maximum flexibility. The wide range of screw compressors from 7 to 11 kW includes fixed and regulated speed models, high efficiency models and is available as airstation including receiver and refrigerant dryer.
Engineering Excellence
Compressors are more than just a financial investment, they are a key component in ensuring that manufacturers, processors and operators receive consistent, high quality low cost air. The screw compression element is the heart of the compressor and therefore CompAir keeps the design and manufacture in-house, using the latest CNC rotor grinding machinery, coupled with online laser technology. The resulting reliability and performance ensure that operating costs will remain low throughout the compressor’s life.
Benefits
Compressor base mounted
Complete package including compressor, dryer and receiver
Small carbon foot print (by mounting the components on the receiver the footprint is reduced up to 55%)
In-house AirEnd
Highly efficient motors
Easy maintenance
Wide regulation range
🔧 Rotary Screw Air Compressors
L Series (7–11 kW) – Detailed Summary
📌 1. Overview
Power Range: 7 kW to 11 kW (≈ 10–15 HP)
Type: Oil-injected rotary screw compressor
Category: L Series (Light to Medium Industrial Use)
Application: Designed for continuous (24/7) operation
👉 These compressors provide a steady and uninterrupted air supply, making them ideal for industrial environments.
⚙️ 2. Working Principle
Uses two helical rotors (male & female)
Air is trapped between rotors and compressed as they rotate
Produces continuous airflow (no pulsation)
👉 Key results:
Smooth operation
Low vibration
High efficiency
📊 3. Technical Specifications (Typical)
Parameter 7.5 kW Model 11 kW Model
Power 10 HP 15 HP
Pressure 7–13 bar 7–13 bar
Air Flow (FAD) ~0.8 – 1.2 m³/min ~1.5 – 2.0 m³/min
Voltage 3 Phase (380–415V) 3 Phase
Cooling Air cooled Air cooled
🔁 4. Fixed vs Regulated Speed
🔹 Fixed Speed Compressor
Runs at constant motor speed (RPM)
Uses load/unload mechanism
Lower initial cost
Simple design
👉 Best for:
✔ Constant and steady air demand
🔹 Regulated Speed (VSD / VFD)
Motor speed adjusts based on air demand
Eliminates unload losses
Saves 20–35% energy
👉 Best for:
✔ Variable or fluctuating demand
🔋 5. Key Advantages
✅ Continuous Operation
Suitable for 24/7 industrial use
✅ Energy Efficient
Lower internal losses compared to piston compressors
✅ Low Noise
Much quieter than reciprocating compressors
✅ Low Maintenance
Fewer moving parts (no pistons, rings, valves)
Longer service life
🏭 6. Applications
Commonly used in:
CNC machines
Automobile workshops
Textile industries
Food & pharmaceutical plants
Spray painting
Packaging units
🛠️ 7. Typical Product Options
🔹 7.5 kW Fixed Speed
Best for small workshops
Cost-effective
Suitable for steady load
🔹 7.5 kW Variable Speed (VFD)
Energy efficient
Ideal for variable demand
Reduces electricity costs
🔹 11 kW Industrial Model
Higher air output
Suitable for large operations
Supports expansion
📊 8. Comparison Overview
Feature Fixed Speed Variable Speed (VSD)
Initial Cost Low High
Energy Efficiency Medium High
Maintenance Low Moderate
Best Use Constant load Variable load
Operating Cost Higher (long term) Lower (long term)
🧠 9. Selection Guide
Choose based on:
Air requirement (CFM / m³/min)
Duty cycle (continuous vs intermittent)
Power consumption & electricity cost
Future expansion needs
✅ Final Conclusion
7.5 kW (10 HP) → Ideal for small to medium operations
11 kW (15 HP) → Suitable for heavy industrial use
Fixed Speed → Best for constant demand & lower budget
Variable Speed (VFD) → Best for energy savings & fluctuating demand
👉 Simple rule:
Constant usage → Choose Fixed Speed
Variable usage → Choose VFD (Regulated Speed)
