Atlas Copco USA - Compressors
Our solutions
Industrial tools & assembly solutions
Power Technique
Power Technique
Small Vehicle Mounted
Large High-Pressure Diesel
Small Towable Diesel
Products and solutions
Oil-sealed vacuum pumps
Products and solutions
Rental fleet
Products and solutions
Energy Storage Systems
Products and solutions
Mobile air compressors
Products and solutions
Electric Variable Compressors
Large High Pressure Diesel Compressors
Large Low Pressure Diesel Compressors
Small Towable Compressors
Small Vehicle Mounted Compressors
Mobile generators
Products and solutions
Large Diesel Generators
Medium Diesel Generators
Small Diesel Generator

Our guide to popular air compressor types

Compressors Compressor Types Choosing an Air Compressor Compressed Air Wiki How-To

After determining the right size machine you need, you'll likely choose between two air compressor types - piston and rotary screw. This decision will be based on your application(s). 

Evaluating both options

When researching air compressor types, it’s worth considering the following points:

●       Application / industry requirements

●       Air flow utilization

●       Pressure needs

●       Air quality and dryers/filters

●       Usage time throughout the day

●       Fluctuating air flow demand

●       Future expansion plans

Piston air compressors

Piston compressors are the most economical, least expensive air compressor to buy

The most economical, least expensive air compressor to buy is the piston or reciprocating air compressor. This equipment, found in many small businesses, is very simple and robust. You can usually find a piston compressor in work, machine, body, and tire shops, as well as light manufacturing facilities.

Piston compressors are relatively easy to maintain and, as previously mentioned, require minimal upfront costs. Despite their relatively low initial investment price, there are some drawbacks worth mentioning. These machines are only meant for intermittent use. They can only work at about 50-60% of their duty cycle.

This reduced runtime means piston compressors run 30-35 minutes every hour, with required downtime. These units need proper cooling time between cycles, otherwise they will overheat or break.

It is also important to understand that piston compressors create a lot of downstream oil. If not treated properly, they can damage machines utilizing compressed air.

Lastly, piston compressors tend to be very loud when operating. This noise can be hard on employees working in close proximity to the machine.

Rotary screw compressors

Rotary screw compressor suit applications that require constant compressed air supply

If your application(s) require constant compressed air supply, you should consider a rotary screw air compressor. Unlike piston compressors, these machines can handle a 100% continuous duty cycle. They're designed and built for reliable, all-day operation.

In addition, rotary screw compressors come with more options than piston machines. Depending on your needs and budget, you can opt for variable speed drive (VSD) or fixed speed engine models. Most rotary screw equipment can also be built with an integrated dryer for clean, dry air.

Furthermore, smaller screw compressors can be tank mounted. This arrangement allows for additional storage capacity, and saves on space and installation costs. When coupled with an integrated dryer, the installation is plug and play.

Variable speed drive (VSD)

Generally the most expensive option in terms of initial investment, VSD air compressors are also highly efficient. Since energy costs make up to 80% of operating any air compressor, they usually pay for themselves. In fact, you can save up to 60% with the latest generation VSD models compared to fixed speed compressors. These energy savings quickly add up to (tens of) thousands dollars per year.

If your facility has a fluctuating air demand, VSD machines are the best choice. This point is especially true if your facility operates multiple shifts during the day, where air flow increases and decreases. VSD engines match output to the required demand.

In simpler terms, the compressor senses how much flow is being used and adjusts its motor speed accordingly - allowing for the necessary output. On slower production days, VSD technology is especially handy. It eliminates wasted electricity from not constantly running at maximum capacity.

It's also worth mentioning that many VSD compressors come with advanced monitoring and control tools to optimize performance. These optional features can collect data and analytics to determine the best operating conditions for your application(s). They also help prevent downtime and save on unnecessary maintenance costs.

VSD air compressors are becoming the norm, rather than the exception. Many customers find the annual energy savings allows them to reinvest money elsewhere.

Of course, if VSD compressors are too costly, there are other options to match your budget. Rotary screw compressors come in a wide range of sizes, and designs. If you know your air demand needs are absolutely stable, you may want to consider a fixed speed compressor.

Fixed speed

As the name suggests, fixed speed models only run at one speed throughout the day. This static operation means you'll receive the same air pressure. It also doesn't run at a low speed when not in use. They still make for a better option than a piston compressor if you need 100% air flow, and are designed for optimal performance.

Other topics when considering air compressor types

Within this article, we touch upon size and air pressure. If you're still uncertain on the right air compressor for you, it's worth reading deeper into these topics. Investing in equipment that's either too big or small can be detrimental to efficiency. Also, when shopping for new equipment, you'll see oil injected and oil free models, briefly covered below.

Choosing the right compressor size

The linked guide below provides information on what to evaluate when considering size. Essentially, you want to pay attention to pounds per square (psi) and bar for your application(s). Pressure is related to the force it takes to move something. If you're working with heavy jobs, you'll need more pressure.

It also goes into flow or free air delivery (FAD). This is measured in cubic feet per minute (cfm), liters per second (l/s), or cubic meters per hour (m3/h). These figures are related to the time it takes to complete a task. You'll need a large air flow to move heavy objects quickly.

Related to air compressor types, these factors are important when investing in new equipment. As highlighted, air compressors come in a wide range of sizes. You'll want the best solution for your facility.

Oil-injected vs. oil-free compressors

We've also created an overview on oil-injected and oil-free compressors. This article covers the most appropriate option for various applications, as well as air quality/purity standards. Essentially, oil injected machines use oil as lubrication for cooling and to reduce friction. This process results in slight traces of oil in the compressed air.

If you work in a sensitive industry, like food or medical, oil-free compressors are usually the best choice. They guarantee 100% clean air, and meet the most strict air quality standards. There are many advantages to both oil injected and oil free, which are covered further in the linked guide.

These two types of air compressors are worth mentioning, especially since both piston and rotary screw equipment come in oil free and injected models.

What Compressor Size do I Need?
15855570 - equipment, cables and piping as found inside of a modern industrial power plant
What Compressor Size do I Need?
Find out what the size of your copressor should be, based on the required air flow and pressure.
Find out what the size of your copressor should be, based on the required air flow and pressure.
Find out what the size of your copressor should be, based on the required air flow and pressure.
Do I Need an Oil-free or Lubricated Compressor?
Air comprimé - Industrie Agroalimentaire - compresseurs à vis
Do I Need an Oil-free or Lubricated Compressor?
Find out whether or not you need an oil-free compressor, or if a lubricated compressor will do the job.
Find out whether or not you need an oil-free compressor, or if a lubricated compressor will do the job.
Find out whether or not you need an oil-free compressor, or if a lubricated compressor will do the job.

We're here to help

Hopefully you've found the information in this guide useful. If you're still undecided on which compressor makes the most sense for you, feel free to get in touch today.

Compressors come in all types and sizes. From massive machines that keep huge production plants running to the small versions that avid do-it-yourselfers are using, there is a compressor for everyone. With so many models to choose from, which one is the right compressor for you? This guide will help you in making the right decision for your business.


Would you like to turn to one our experts? They are happy to assist you in finding the optimal compressor.


Related Articles

an illustration about the types of compressors for the atlas copco wiki.

The Piston Compressor

Learn more about air compression and the different types of displacement compressors we know today. Here we’re talking about oil-lubricated and oil-free piston compressors.

Check out our wide range of reliable, energy-efficient and cost-effective air compressors. For all your low, medium and high pressure applications.