How To Size an Air Compressor

There is no “one size fits all” in the industrial air compressor realm. Because your air compressor is so vital to your operations, it is best to have an expert size your compressed air systems to your applications.  Doing this ensures you are operating at maximum efficiency and have the correct type of compressor for your needs.  Zorn Compressor has tons of local experts ready to help you do this! However, sometimes it can be overwhelming trusting someone else as they size such an important part of your facility.  Here’s the logic behind what we are doing and why, to help size the perfect compressor to your facility!

Steps To Size a Compressor

Determine Your Required Flow

First up, you need to determine the amount of flow that your applications require, also known as CFM (cubic feet per minute).  To find this, you need to measure average CFM but also high- and low- demand periods too.  To learn how to find the correct CFM for your applications, visit our other blog post, THE CFM VS. SCFM VS. ACFM VS. ICFM MONSTER, to learn how to calculate and what factors to take into consideration.

It is important that you find your CFM needs per tool utilizing compressed air power. Most tools will list the necessary CFM needed to operate properly.  If your compressor is power multiple tools, you will need to add up the CFM requirements of each tool to find the necessary CFM your compressor will need to provide to operate them simultaneously. If the tool does not list a CFM requirement, then you will need to check the product manual or contact the manufacturer.

Determine Your Required Pressure

Pressure, or PSI (pounds per sq. inch), is the amount of force your compressor needs to produce to perform the amount of work necessary for completing a given task. Unlike CFM, you do not need to add together all the PSI requirements of each tool.  You still need to be aware of each tool’s PSI requirements, but you only need to use the highest one- because that is the highest PSI your compressor will need to reach to successfully operate all tools.

Know Your Voltage Supply

The type of electricity being supplied to your building is crucial to sizing and identifying the right type of compressor.  Industrial air compressors require a strong and sufficient energy source to operate.  Is it single-phase or three-phase? What is the voltage? Knowing these will help you understand what compressor will be able to operate with this power supply to reach the necessary pressure and flow.

Understand Your Environment & Applications

Different environments and applications dictate the kind of compressor that will be appropriate for your situation.  For example, medical or food grade operations are held to higher standards than painting or automotive applications.  These higher standards may dictate that the compressor needs to be oil-free or may dictate the kinds of materials used in transporting the air to the point of use. Different applications also bring about different tools and in all different amounts- a compressor operating more than 1 tool may require less CFM & PSI than a compressor operating 6 different tools.

If your compressor is located further away from the point of use, you will need to utilize more piping.  The longer the pressurized air needs to travel before it is released, the more likely for a pressure drop. So, to avoid needing an oversized compressor you will need to increase pipe size.

Depending on where your compressor is located also will dictate the kind of compressor necessary depending on preferred noise levels, control types, and traffic levels.

Remember, smaller air compressors will normally require a storage tank.  A great rule of thumb to follow is a tank of 5 gallons per CFM.  The size of the compressor alongside the tank may change where your compressor is located, thus requiring you to reassess the previously mentioned environmental factors.

Know Your Duty Cycle Requirements

Your compressor’s duty cycle refers to how hard your compressor needs to work to meet your demand. The standard formula for a start/stop control compressor is (Compressor Time On/ (Time On plus Time Off) = Duty Cycle Percentage.)  

Why Air Audits Are Important

Regularly conducted air audits ensure that your system is operating properly and at maximum efficiency.  By proactively maintaining and auditing your system, you will reduce short- and long-term costs associated with using compressed air.

The top reason customers regularly perform compressed air audits is to lower energy costs, because, as we all know, energy can be expensive! In general, up to 50% of generated compressed air is wasted, so if there is also a leak in your system, this number can increase astronomically causing financial stress from excessive energy usage. Conducting regular air audits can assess and identify the issues causing problems or increases in your costs.

Aside from saving energy, performing regular air audits can increase your systems reliability, extend its lifespan, and point out areas that may need to be upgraded or expanded.



Zorn is the Midwest leader of custom, engineered compressed air and vacuum solutions. We provide the best customer experience by understanding your applications and needs and offering an unparalleled commitment to customer satisfaction. 

Our comprehensive product and service solutions keep you running 24/7.

  • Reliable equipment
  • Trusted brands
  • Seamless, easy installation
  • Post-sales support
  • Local, 24/7 service

Our compressed air experts look forward to meeting you to discuss your equipment and support needs. Please contact us directly at (262) 695-7000 with any questions or to schedule service for your system moving forward.

Contact us today!