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What Do You Need to Know When Buying Air Compressors?

by Nick Calvo on May 06, 2020

Knowing Compressed Air Equipment


CFM is a measurement of AIR FLOW in Cubic Feet per Minute. Larger motors on compressors will produce more air – or higher CFM’s. Numerous tools operated at once or more technicians using air will increase the air demand on an air compressor. Processes that continuously use air – such as paint spraying – will use much more air than intermittent use of tools such as pneumatic wrenches. Depending on the task the compressed air is performing – either intermittent use or continuous use – different types of air compressors are recommended. A rotary type compressor is best for continuous duty cycles, while a reciprocating compressor is best for occasional use because it requires down time to cool off.


PSIG is a measurement of PRESSURE in Pounds per Square Inch as read on a Gauge. Air compressors can generate and discharge air at several different pressures – such as 100, 125, 150, or 175 psig. What pressure is needed depends on the tool or process the air is used for. Air tanks or receivers are filled with compressed air, and store it for later use without putting a direct demand on the air compressor. As the air in the receiver is used the pressure lowers. When the pressure is low enough to reach it’s set point – the compressor will kick on and start compressing air again to raise pressure back up.

Compressed Air USA


HP is a measurement of HORSEPOWER. The higher the horsepower, the more generating power of a compressor to maintain high flow rates of air. Higher horsepower will keep up with a systems air demands while in use, or charge air tanks or receivers at a faster rate. CFM can be estimated by Horse Power.
Reciprocating Air Compressors: (Horse Power) x (4) ≈ CFM
Rotary Air Compressors: (Horse Power) x (4) ≈ CFM


Tank Capacity

TANK CAPACITY is a measurement of AIR VOLUME in Gallons. Compressors can supply an air system, and store air in tanks or receivers. Compressors can be built together with air tanks or be independent of them. The bigger volume or larger gallon size of a tank means it can store more air. With more volume of air, higher flow rates or longer periods of discharge can be achieved when coming out of the tank.

Configurations of Equipment

CONFIGURATIONS of equipment can be BASE MOUNTED, TANK MOUNTED, HORIZONTAL, VERTICAL, and even PORTABLE. Depending on preference or application, there is a configuration to meet those needs. Base mounted units are ideal for large machines that supply large air loads, however, they require an air tank or receiver to store the air produced. Tank mounted units can be more compact, if floor space is important. Tank mounted units with built-in air dryers are even more compact, considering there is no extra piping or floor space needed for the dryer. Portable units can bring air to the job site, whether it be hand carried, wheeled, truck mounted, or towed.


POWER to equipment is provided by either ELECTRICITY, GASOLINE, or DIESEL. The most common compressor applications use Electrical Power within a facility. Electrical Ratings include the following: Voltage, Phase, and Frequency.

Voltage can be either 115, 208, 230, or 460 Volts. Some equipment can even run off multiple voltage variations – for example: 115V and 230V. Other equipment can be rewired in the electrical hub to accept different voltages. This makes supplying power more convenient, and more versatile for facilities.

Phase can be either Single Phase or Three Phase.

Frequency is 60Hz for all of our equipment.

Gas or Diesel engines are typically found on portable compressors.

Compressed Air USA

by Elle Jones on April 26, 2023

I was given the responsibility of purchasing new compressor components to swap out the worn-out and broken ones in the tools and gear we use at work. I appreciate you informing me that there are several air compressor layouts and that base-mounted units are often utilized for large machinery that needs to produce larger air loads. When searching for a retailer who can offer me compressor components at a reasonable price, I’ll keep this in mind. https://www.sscair.com/

by Taylor Abrams on February 20, 2023

I was given the responsibility of purchasing new compressor components to swap out the worn-out and broken ones in the tools and gear we use at work. Thank you for informing me that either ELECTRICITY, GASOLINE, or DIESEL provides POWER to equipment. The majority of compressor applications at a facility make use of electrical power. While searching for a vendor who can provide me with Energy Efficient Compressors at a competitive price, I’ll keep this in mind.

by Razel on October 13, 2022

Thanks for sharing such a useful information with us. This article help me to select air compressor for me. If someone looking for more information, i would like to suggest one more sources here. Hope you will find this helpful. https://thirstycraftsman.com/

by Charlotte Fleet on September 15, 2022

Thanks for explaining how it is important to consider tank capacity so you can find an air compressor that can store more air. I’d recommend looking for air compressor units from a supplier that specializes in your specific industry. That way, you can be sure that the air compressor equipment will meet all the needs of your company. https://www.hydeng.com/sales-service/hydraulics/

by Amy Saunders on May 30, 2022

Phew! I’m so glad you reiterated that tank mounted air compressors are perfect if we need them to be placed at a small area with limited space. My basement is going to be transformed into a small workshop as what my husband wished since almost a year ago and there are lots of tools to be installed there. I have to remind him about this so he can make a proper installation. http://www.airdraulicsinc.com/automotive-equipment-air-compressors

by Anna Collins on April 28, 2022

I got tasked to buy new compressor parts to replace the old and damaged ones in the equipment and machinery we use for work. Thanks for letting me know that there are different configurations of equipment for air compressors, and that based mounted units are usually the ones used for large machines that require larger air loads to supply. I’ll keep this in mind when I look for a dealer that can sell me compressor parts at a good price. https://www.compressedair-systems.com/parts

by Kenneth Jenson on April 06, 2022

Thanks for your helpful article

by Kenneth Jenson on February 17, 2022

This article helps me to select air compressor.When I buy something I always read read buying guide.This buying also assist me.

by Compressed Air USA on July 30, 2020

We usually recommend a small portable electric reciprocating air compressor, sized 2HP to 5HP, but for sanding/grinding/paint spraying that may be too small to continuously supply air to those loads. I would recommend either a 4HP or 5HP stationary reciprocating air compressor, with a 60 or 80 gallon tank. Check out our CFM Calculator to determine what your air demand could be, and size your machine accordingly. If you undersize a reciprocating air compressor, it will run too long and not take breaks to cool. If you oversize an air compressor, it won’t hurt because it will charge the receiver and store plenty of air for your use. However, too big of a machine takes up space, and requires more energy to run.
Contact us with any questions! 904-548-6200 or email INFO@compressedairusa.com

by Dan mackey on August 05, 2020

Hi I just bought a house and it has a garage I was wondering what kind of compressor I would need for the application I would be using it for, I’d mainly be using it for air tools for mechanic and body work i.e impacts, sanders, paint guns and air brush any info/direction would be great thanks.

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