Most workshop tools run at around 6 bar, and an 8 bar compressor supplies them without difficulty. So why are there 10, 13 and 16 bar compressors? Because some uses genuinely need them. For everything else, higher pressure costs air flow and electricity and brings nothing.
Who needs more than 8 bar?
| Pressure | Typical uses | At AIRSTAHL |
|---|---|---|
| 8 bar | Everyday tools: impact wrenches, sanders, blow guns, spray guns | S and K series in 8 bar, E 75 and E 110 |
| 10 bar | Long networks or tools that need a margin, large pressure drops to make up | S and K series in 10 bar, S 220 PM |
| 12.5 to 13 bar | Truck and plant tyre inflation, demanding tools, machines that need a high inlet pressure | S and K series in 13 bar, E 75 in 12.5 bar, two-stage E 75 HP |
| 16 bar | Laser cutting with compressed air | L series, 8 to 16 bar |
The right starting point is still your tools and machines: the working pressure of the most demanding one, plus the pressure drop in the network, plus a control margin. The full method is in calculating the pressure you need.
Every extra bar costs air flow
At the same power, a compressor that compresses harder delivers less air. This is true of every compressor, and our data sheets show it clearly:
| Model | 8 bar | 10 bar | 13 bar |
|---|---|---|---|
| S 75 and K 75, 7.5 kW | 1.1 m³/min | 0.95 m³/min | 0.8 m³/min |
| S 110 and K 110, 11 kW | 1.7 m³/min | 1.4 m³/min | 1.1 m³/min |
| S 150 and K 150, 15 kW | 2.2 m³/min | 2.0 m³/min | 1.6 m³/min |
Going from 8 to 13 bar loses about a third of the air flow on an 11 kW machine. If your tools do not need 13 bar, that is air you pay for without using it. The flow and pressure converter helps compare machines quoted in different units.
Screw or piston for high pressure?
- Piston compressor: the E 75 comes in 8 bar and 12.5 bar. The E 75 HP is two-stage: the air is compressed once, cooled in an intercooler, then compressed again. It reaches 12.5 bar with cooler air and a compressor unit that runs cooler. It is designed for truck tyre inflation and plant workshops, where air is used in bursts.
- Screw compressor: the S and K series can be ordered in 8, 10 or 13 bar. They suit uses where high pressure is needed for long periods, continuously or nearly so.
- 16 bar: the L series combines a variable speed screw compressor from 8 to 16 bar, a 16 bar air receiver, a refrigerated dryer and precision filtration. It is built for laser cutting, which needs both pressure and very clean air: see which compressor for laser cutting.
The whole installation must keep up
A 13 or 16 bar compressor is no use if the rest of the network is not rated for that pressure.
- The air receiver: its maximum working pressure must be at least equal to the compressor's. A 10 bar air receiver cannot take a 13 bar compressor. We offer, for example, a 13 bar vertical air receiver, and the L series has its own 16 bar air receiver built in. Installation and inspection rules are in our guide on air receiver regulations.
- The dryer, filters, hoses and fittings: each has a maximum pressure, to be checked before connecting.
- The safety valve: it must match the pressure of the air receiver and the compressor.
More pressure, more energy
The higher the pressure required, the harder the compressor works. Every unnecessary bar increases the electricity bill and makes network leaks worse. If your tools run at 6 bar, it is better to reduce pressure drop (pipes of the right size, fittings in good condition, clean filters) than to raise the pressure to make up for it. The electricity cost calculator gives an idea of what your compressor costs to run.
When only one workstation needs high pressure, a good solution is not to push the whole workshop to 13 bar: you can dedicate a machine to that workstation and leave the rest of the network at its normal pressure. Tell us about your tools and machines in a quote request: we will suggest the right pressure and model.
For your trade: Compressor for truck workshops, Compressor for metalwork and fabrication shops, Compressor for agriculture.