How Do You Size a Piston Air Compressor?
Contact an expert to help you size the correct piston for your business.
October 19, 2017
Learn how to properly size your piston compressor based on your needs
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 horse power. Single stage air compressors have a maximum pressure of around 130 psi (9 bar) while two stage air compressors have a maxinum 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
- 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
| Tool/Equipment | Air Pressure (psi) | Air Pressure (bar) | Air Consumed (cfm) | Air Consumed (l/s) |
| Impact Wrench 3/8-1/2 | 70-90 | 4.8-6.2 | 5 | 2.36 |
| Impact Wrench 1/2-3/4 | 70-90 | 4.8-6.2 | 10 | 4.72 |
| Impact Wrench 3/4-1 3/4 | 70-90 | 4.8-6.2 | 20 | 9.44 |
| Air Ratchet | 70-90 | 4.8-6.2 | 3-5 | 1.42-2.36 |
| Body Sander (Oribital) | 70-90 | 4.8-6.2 | 12 | 5.66 |
| Tire Changer | 125-150 | 8.6-10.3 | 2 | 0.94 |
| Bead Breaker | 125-150 | 8.6-10.3 | 12 | 5.66 |
| Blow Gun | 70-90 | 4.8-6.2 | 3 | 1.42 |
| Die Grinder | 70-90 | 4.8-6.2 | 7 | 3.3 |
| Screwdriver #2-6 Screw | 70-90 | 4.8-6.2 | 5 | 2.36 |
| Screwdriver #6-5/16 Screw | 70-90 | 4.8-6.2 | 10 | 4.72 |
| Paint Spray Gun (Touch Up) | 70-90 | 4.8-6.2 | 4 | 1.89 |
| Paint Spray Gun (HVLP) | 40-60 | 2.7-4.1 | 15 | 7.08 |
| Nailers/Staplers | 70-90 | 4.8-6.2 | 2-4 | 0.94-1.89 |