Air compressors should be sized based on the volume of air (cfm/m3h) and air pressure (psi/bar) needed to do the job and not horsepower. Single stage air compressors have a maximum pressure of around 130 psi (9 bar) while two stage air compressors have a maximum air pressure of 175 psi (12 bar). Tank size is typically not a critical factor in sizing a compressor.
Calculating your need
- What is the maximum pressure you need? (refer to the table below for a general guideline)
- What is the electrical requirements (voltage/phase)?
- How many people will be using air at any time (maximum)?
- Is this a body shop or mechanical shop? Body Shop: 12-15 cfm/person X # of people and Mechanical Shop: 3-5 cfm/person X # of people.
- Now add at least 25% to your total cfm required in order to allow for duty cycle.
Typical cfm consumption by tool
