Guide
What size air compressor do I need?
Add up the air (LPM or CFM) of every tool that runs at the same time, add about a quarter for leaks and growth, and choose a compressor that delivers at least that at the pressure (bar) your tools need. Tank size comes last.
By Everest Hydro Pneumatic Solutions, Pimpri-Chinchwad, Pune. Updated .
1. Air delivery (LPM or CFM)
Every air tool uses a set amount of air, shown as LPM (litres per minute) or CFM (cubic feet per minute). 1 CFM is about 28.3 LPM.
Add the tools that run together, not every tool you own. Then add about 25% so the compressor is not running flat out.
2. Pressure (bar)
Most air tools work at 6 to 7 bar, so a compressor rated 8 bar covers them. Some jobs need more. Check the tool's label.
3. Tank size
The tank stores air for short bursts and lets the motor rest. A bigger tank does not make more air. Spray painting and sandblasting benefit from a bigger tank.
4. How long it runs
For on-off use, a reciprocating or oil-free piston compressor is usually enough. For air all day, a screw compressor suits better.
5. Power supply
Smaller units run on single phase. Larger units need three phase. Check your site supply before you buy.
Oil-free silent compressors →Reciprocating compressors →Screw compressors →Glossary →
Questions.
- Is HP enough to size a compressor?
- No. Two compressors with the same HP can deliver different air. Compare air delivery (LPM or CFM) at the pressure you need.
- What size compressor for a dental chair?
- It depends on the chair. Tell us how many chairs run together and we suggest a model.