How do I size an air compressor for a repair shop?
Short answer: Add up the air consumption of the tools likely to run at the same time, allow a margin for growth and leaks, and choose a compressor that supplies that flow at the required pressure with a suitable duty cycle and tank.
Air tools are rated by the flow they consume at a given pressure. Impact wrenches and ratchets use air in bursts, while sanders, grinders and blowguns may run continuously. A shop with several technicians may have multiple tools running at once.
Estimate how many tools run simultaneously and their consumption, add a margin for leaks and future growth, and compare with the compressor's delivered flow at working pressure, not its displacement. Duty cycle matters; piston compressors often need rest periods, while rotary screw units are designed for continuous running.
Plan the piping with adequate diameter, drops with filters and regulators, and drains for water. Install the compressor in a ventilated area, follow electrical codes, and inspect the tank and relief valve regularly. Drain the tank daily to remove water.
Tools used for this job
General guidance only. Follow the vehicle and tool manufacturer's procedures, and confirm vehicle coverage on the tool maker's list before buying.