There are lots of different applications for air compressors, so how do you choose the right air compressor for the job? A little understanding of air compressor basics should help in finding the right tool for the job.
Air compressors use a motor (typically a single stroke electric, gasoline or diesel engine) to compress the air and store it in a tank that can withstand high pressures. Consumer-grade and professional-grade air compressors are used for a variety of purposes, including powering pneumatic (AKA air powered) tools and pneumatic HVAC control systems, filling air cylinders, inflating tires, powering sand blasters and other finishing and cleaning systems, and more.
When deciding how to buy the right air compressor, you should first identify your needs and potential uses. Keeping your intended uses top-of-mind makes it easier to dismiss the many air compressors in the marketplace that don’t address those needs.
Determine the air compressor's location
First, consider where you will use your air compressor. Will you use it on job sites in the field, or will you use it in the same place all the time, such as in a workshop or on the factory floor? If you plan on using a portable air compressor, will you always have access to electricity? If not, a gasoline, diesel or battery-powered air compressor may be your best bet.
Determine the air compressor's specifications
Next, consider how much compressed air you will use and how quickly you will use it. For most applications, you will want either a single stroke, or a dual stroke engine. If you will be using a lot of pressurized air quickly, you’ll want your compressor engine to be capable of more piston strokes (or stages). Regardless of the type of engine, all air compressors use at least one piston to compress the air and push it into a tank. To do this, the piston’s motion sucks free air into a cylinder, momentarily trapping it there. The trapped air is then compressed to approximately 120 psi and pushed into the tank by the single stroke of the piston. Dual stroke (or dual stage) air compressor engines have two pistons, which compress the air in two separate stages, thereby doubling the amount of compression. Each stroke pushes more air into the tank, thereby further compressing (pressurizing) the air.
Air velocity, pressure, and engine power are additional specs to be aware of when contemplating the purchase of an air compressor. These are indicated by numbers corresponding to CFM, PSI and horsepower, respectively.
Think of CFM (cubic feet per minute) as air velocity or air delivery rate. It is the amount of free air inhaled via the compressor’s intake port per minute. It is also the maximum amount of air a compressor can generate at a particular pressure level. The higher the CFM, the higher the mass of air flowing per minute, and the faster the air-powered tool will work. If you are powering multiple applications or tools at once, or if the air compressor will be used for large jobs, a higher CFM is required.
PSI, or Pounds per Square Inch, is a measure of pressurized air. In the case of an air compressor used to drive air-powered tools, for example, the higher the PSI, the more air force is transferred to the tool for a harder drive. PSI determines CFM. Most air tools require a PSI of between 40 and 90.
Horsepower is actually more of an efficiency consideration when it comes to air compressors, and less a factor of actual power. If a lower horsepower compressor and a higher horsepower compressor can both generate the same PSI at a particular CFM rate, the lower horsepower compressor is operating at higher efficiency since it draws less power to generate the same result.
While air compressors with tanks of up to 50 liters are typically used for spray painting, tool driving and similar jobs, larger capacity compressor tanks are used for pneumatic applications in workshops and manufacturing. In general, the following chart presents examples of specs for air compression relative to particular applications.
The right Air Compressor for your applications
| Application | Required Air Pressure (PSI range) | Air Consumed (CFM) |
| Air Ratchet | 70-90 | 3-5 |
| Bead Breaker | 125-150 | 12 |
| Blow Gun | 70-90 | 3 |
| Car Lift (8,000 lbs.) | 145-175 | 6 |
| Chisel Hammer | 90 | 3-11 |
| Die Grinder | 70-90 | 7 |
| Disc Grinder | 90 | 5-8 |
| Drill | 90 | 3-6 |
| Engine Cleaner (Spray Gun) | 90-100 | 5 |
| Grease Gun | 90 | 4 |
| Impact Wrench, ⅜” - ½” | 70-90 | 5 |
| Impact Wrench, ½” - ¾” | 70-90 | 10 |
| Impact Wrench, ¾” - 1¾” | 70-90 | 20 |
| Nailers/Staplers | 70-90 | 2-4 |
| Orbital Body Sander | 70-90 | 12 |
| Paint Spray Gun (Touch Up) | 70-90 | 4 |
| Paint Spray Gun, HVLP (High Volume, Low Pressure) | 40-60 | 15 |
| Screwdriver, #2-6 Screw | 70-90 | 5 |
| Screwdriver | 70-90 | 10 |
| Shears | 90 | 8-16 |
| Speed Saw | 90 | 5 |
| Tire Changer | 125-150 | 2 |
The above information is intended as an approximate guide for purchase considerations and is based on averages; it should not be considered accurate for particular tools. Always check with manufacturers for actual air consumption specs.
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Lastly, be sure to consider which air compressor accessories you’ll need such as filters, throttle controls and parts, maintenance kits, remote starts, tanks, and more.
With a little forethought, finding the right air compressor for the type of work you do becomes a lot easier. Zoro carries a variety of consumer, professional, and light industrial air compressors for a variety of uses.
Product Compliance and Suitability
The product statements contained in this guide are intended for general informational purposes only. Such product statements do not constitute a product recommendation or representation as to the appropriateness, accuracy, completeness, correctness or currentness of the information provided. Information provided in this guide does not replace the use by you of any manufacturer instructions, technical product manual, or other professional resource or adviser available to you. Always read, understand and follow all manufacturer instructions.