How to size a workshop air compressor
Match delivered airflow and working pressure to simultaneous demand, then confirm air quality and installation conditions.
List every air user
For each machine or tool, record the required pressure, air consumption and how long it runs. Mark which users operate together. Share the equipment manuals or nameplate data with the supplier so assumptions can be checked.
Compare flow at the required pressure
Motor horsepower alone does not describe delivered air. Compare free air delivery (FAD) at the stated operating pressure, using the same units and reference conditions. Pressure and flow are different requirements and both must fit the application.
Include air treatment and distribution
Ask the equipment supplier what air quality is required at the point of use. Include the dryer, filtration and distribution layout in the discussion rather than choosing the compressor in isolation. Confirm requirements from the actual equipment documentation.
What to send for sizing
A demand survey or measurement is especially useful when replacing an existing system. Final sizing should be checked against the site and operating pattern.
- List of air users with pressure and flow requirements
- Which equipment runs simultaneously and the shift pattern
- Existing receiver, dryer, filters and distribution network
- Planned additions, installation environment and available electrical supply