How to Choose the Right Air Compressor for CNC
Choose the compressor from the machine's real airflow, pressure, duty and air-quality requirement — then size the receiver, dryer, filtration and pipework as one coordinated system.
Start With the CNC Machine — Not the Compressor
The correct compressed-air system is determined by the machinery manufacturer's airflow, pressure, duty and air-quality requirements. Motor kW alone is not a reliable sizing method, and laser power does not directly tell you compressor CFM.
The Five Figures You Need
Pressure: Avoid Generic Laser Rules
Some laser applications may use assist-air pressures around 10–16 bar or higher, but there is no universal design range. Use the exact laser manufacturer's figure for the material, nozzle and approved process.
Standard workshop compressors may be unsuitable for a high-pressure laser application, but that conclusion should come from the machine specification rather than a generic pressure band.
Choose the Compressor Technology From the Demand Profile
Fixed Speed
Can be a strong choice where airflow demand remains high and stable for long periods.
Variable Speed
Can reduce unnecessary unloaded running where CNC machines and other users create a genuinely changing load.
Clean, Dry Air: Follow the Machine Specification
A refrigeration dryer suits many industrial applications, but it is only correct where its achievable pressure dew point meets the CNC or laser specification. More demanding dryness may require another dryer technology.
- Size the dryer from actual airflow and apply inlet-temperature, ambient-temperature and pressure corrections.
- Select filter stages to achieve the required particle and oil cleanliness.
- Account for filter and dryer pressure drop.
- Maintain drains and condensate treatment.
- Do not assume oil-free automatically means dry or particle-free air.
Receiver and Pipework
A receiver supports short peaks, pressure stability and compressor control, but it cannot compensate indefinitely for insufficient compressor output. Pipework must also be sized to deliver the required flow without excessive pressure loss.
Real Installation: KUT Machinery
The KUT Machinery showroom system combined a TAN-S 22VSD, TAN-RD-36 refrigeration dryer, filtration, 500-litre vertical receiver and distribution pipework. The important point is that the system was selected around the combined machinery and showroom demand — not because every CNC site needs a 22 kW compressor.
CNC Compressor FAQs
How do I size an air compressor for CNC machinery?
Use the exact machine airflow at its required pressure, then add realistic simultaneous demand from other users and account for system losses.
Can I size by compressor kW?
No. Similar motor powers can deliver different airflow at different pressures.
Does every laser need 10–16 bar?
No. Use the exact manufacturer's pressure requirement for the approved process.
Do I need a refrigeration dryer?
Only where its achievable pressure dew point meets the machine specification.
Is VSD always better for CNC?
No. It is most useful where total demand varies materially. Stable high demand can favour fixed speed.
Can a receiver make up for an undersized compressor?
Only for short peaks. It cannot supply sustained demand indefinitely.
Need a CNC System Sized Properly?
Send us the machinery model, airflow, pressure, duty and air-quality requirement. We can assess the compressor, receiver, treatment and pipework together.