Commercial Air Compressor Buyer's Guide

The Industrial Revolution ushered in the ability to harness massive power and build titans of industry. Today, industries are still built with engines more powerful than ever, and one of the machines that has stood the test of time is the commercial air compressor. 

These behemoths deliver compressed air power to large autobody shops, factories, and entire manufacturing plants. When it comes to a buying decision that can dramatically affect the profitability of a business, a unit is required that exceeds requirements, works efficiently to save valuable dollars, and is built to last until the next industrial revolution. 

This article guides readers through the important information necessary to ensure the right type of commercial compressor is chosen, including the steps required to size it properly for any job. 

How to Pick the Perfect Industrial Compressor 

Professional air compressors pack a punch regardless of the type, but there are three distinct styles to choose from before making further decisions or proceeding to sizing. For more information on how each type of compressor is powered, it is recommended to first read the Air Compressors 101 Guide to learn how each type works in detail. 

Commercial-Grade Reciprocating Compressors 

This is the most common type of compressor seen in small to medium-sized businesses; it is powered by a reciprocating piston that pushes air into the compression chamber. 

An important factor to understand is that these air compressors are notoriously louder than others because internal parts rub together while working, creating friction and heat. They can be compared to a supercharged car engine when the pedal is stomped on—powerful, but loud and not very efficient. 

Single-piston or single-stage models tend to be noisier than dual-piston (also called two-stage) reciprocating air compressors. This is because two pistons work half as hard, as each piston can operate at half the revolutions per minute (RPM) and deliver the same amount of power as a single-piston unit. However, technology is increasingly changing, and newer, much quieter reciprocating air compressors are available on the market today. 

Rotary Screw Air Compressors 

Rotary screw air compressors are very powerful and are quieter than piston compressors. They are designed to run all day long without breaking a sweat. If a business has a greater than 60% duty-cycle need, a rotary compressor is the recommended choice. In applications where air demands are constant and heavy, these compressors provide ease of use and long-term savings. 

They also feature variable-speed drives that run at exactly the level needed—no more and no less—maximizing power, efficiency, and energy savings. They often provide compressed air for precision tasks such as powder-coating or sand-blasting. 

Oil-Free Scroll Air Compressors 

Scroll air compressors are oil-less, quiet, and efficient. They are an ideal choice for lab facilities, pharmaceutical manufacturing, or any application that demands clean, dry, oil-free compressed air. 

Because these compressors are oil-free, they require very little maintenance, and because the internal components do not touch, they operate extremely quietly. They are also highly efficient when used for the proper job. Companies in industries that rely on clean, oil-free air often utilize scroll compressors for their quiet operation and energy efficiency. 

How to Size a Commercial Air Compressor 

Choosing the right type of air compressor is the straightforward part. The challenge lies in ensuring it is sized correctly while accounting for the future growth of a business. It is better to measure twice and buy once, especially since these compressors are large investments. The steps outlined below allow for the proper sizing of a compressor based on air demand, energy guidelines, and HP/CFM/PSI requirements. 

Air Demand Requirements 

These ratings are the first and most important decisions to make when sizing a compressed air system. Regarding Horsepower (HP), a higher rating indicates more potential for satisfying higher air demands; therefore, higher HP ratings generally equal a higher CFM rating on the compressor. 

Cubic Feet per Minute (CFM) is the measurement of exactly how much air a compressor can produce and move through the system every minute. A higher CFM rating equals more compressed air at the desired Pounds per Square Inch (PSI) rating. Both CFM and PSI ratings coincide with air tools and other equipment to provide an idea of the "air demand" cost to run each piece of equipment. If multiple tools are running or large systems are being powered, higher CFM and PSI ratings are necessary because more resources (air volume) are used to accomplish the job. 

If a low duty cycle is expected despite high air demands, a two-stage compressor should be considered over a rotary unit. Because rotary compressors are meant to run constantly, they can become problematic if they are left idle for long periods. This is an important consideration when deciding which style of compressor works best for a specific application. 

Single-Stage Vs Two-Stage Compressors 

In the realm of commercial compressors, single-stage units are mostly reserved for hobbyists or homeowners performing automotive work, airbrushing, or running a small shop that requires a larger stationary air compressor tank. 

However, most commercial facilities or manufacturing applications require a two-stage compressor to keep up with air demands. Two-stage air compressors compress the same air twice, providing almost twice the PSI and significantly more power than a single-stage unit. 

Single-Phase Vs Three-Phase Voltages 

Voltage is vital when sizing any air compressor because a unit will not function unless its voltage type matches the power source. Single-phase power is the standard supply found in homes, apartment buildings, and most small businesses. 

There are limitations with single-phase power; many manufacturers only go as high as 7.5 HP for these units. While some companies, such as Emax or Industrial Air, offer up to 10 HP in single-phase, the selection is limited. Beyond that point, three-phase power is the only option. 

Commercial facilities and industrial buildings are often wired with three-phase power, which is more efficient and produces smoother electrical power, though it is more expensive to install. If a building is wired with three-phase power, the chosen compressor must also be built for three-phase hookups. Consulting an electrician and checking local codes is always recommended before purchasing. 

Other Important Sizing Tips for Industrial Compressors 

• Tank size (in gallons): A larger air tank is useful for longer run times, but takes longer to fill. 
• Tank orientation: Styles include horizontal or vertical, with vertical models being better suited for areas with limited space. 
• Loudness: Rotary screw compressors are quieter than reciprocating compressors, though both have improved with technology designed to reduce operational noise. 

Tools & Accessories for Industrial Compressors 

Accessories for an industrial compressed air system can be added as needed. Components to consider include additional air tanks for storage, air dryers, regulators, and filters to keep the system running cleanly. 

Additionally, air delivery systems are required to transport air to the point of use. While air lines were traditionally made of steel or black piping, new options allow for immediate and endless customization of the direction and flow of lines without the risk of rust. This newer technology is lighter, just as durable as traditional piping, and easier to manage overall. 

Air Treatment for Commercial Compressors 

Air treatment is vital for industrial compressors that work throughout the day. Using untreated air is a fast way to damage a compressed air system, potentially costing thousands in replacements. 

Whether a compressor is used for automotive painting or powering air tools, air treatment is a necessary part of the process. Removing water and contaminants can prolong the life of air tools and ensure paints are applied smoothly.