An air compressor is an invaluable tool to most mechanics in the professional shop and at home. However, many have trouble determining the differences between the single stage vs two stage air compressor. This guide looks closer at the air compressor: single stage vs two stage, so you can determine which is best for you.
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Single Stage Air Compressors (Overview + Pros & Cons)
What is the difference between a single stage and two stage air compressor? Let’s start with the basics of how the single stage air compressor works. These rotary screw compressors are built with one set of rotors located in a single stator housing. It is most often driven by the motor shaft with the help of gears. Sometimes, it is driven by a pulley and belt configuration instead.
You can find single stage compressors in a variety of sizes. In some cases, you can get up to 600-horsepower models for the heavy-duty jobs you have in front of you. Plus, this type of compressor usually doesn’t require a lot of setup to get started or tons of maintenance to remain running.
The single stage compressor is a low-cost option in the grand scheme of things. Therefore, it's most often chosen when a budget must be kept. However, there's no lack of power, and this compressor is capable of just about anything when it has enough horsepower. With that said, there are still some disadvantages to the single stage air compressor.
Advantages
Drawbacks
Two Stage Air Compressors (Overview + Pros & Cons)
Are you starting to see the difference between a single stage and two stage air compressor? The latter of the two is still a rotary screw type of compressor, but it contains a dual-rotor operation. These two synchronized rotors are also housed in the stator but can sometimes be placed in separate housings that are bolted together in tandem.
Intercoolers within the machine remove heat from the first stage of the compression. With these intercoolers, the unit becomes much more efficient, making it more cost-effective to run. However, these machines cost more upfront, so the cost savings need to be weighed.
If the compressor is run at 100% full load most of the time, this is when the true advantages are seen. While you might spend 30% more to get a comparable machine, you will see the savings quickly if you are consistently running the compressor.
Additionally, the two-stage compressor can be very limited in horsepower range. You won’t find many models with more than 125 horsepower because of the lack of manufacturers producing these units. Additionally, you will need a more advanced installation. You can’t just mount the air compressor to a tank, so you must think about the footprint of the design.
Advantages
Drawbacks
Single Stage Vs Two Stage Air Compressor: Key Differences Explained
1. Power
A difference between the single and two stage air compressor is the power capability. With the single stage compressor, you can get a lot more power, even ranging up to 600 horsepower models. However, with the two stage compressor, power is limited, with maximum models ranging up to 125 horsepower. With either model, most mechanics have the power needed to do everyday jobs.
2. Pressure
Another difference between a two stage and single stage air compressor is the amount of pressure that can be released. With a single stage compressor, nothing is stopping the pressure from coming out at full blast. However, the two stage air compressor has more happening behind the scenes, causing there to be more restriction with the pressure that is released.
3. Life expectancy
The life expectancy is going to be different between the two stage air compressor vs single stage. In general, the single stage compressor isn’t going to last as long as the two-stage model. With that said, they should both provide plenty of life, but you will need to perform some additional maintenance with the two-stage compressor.
4. Reliability
One big difference between the single vs two stage air compressor is how reliable each is. The single stage compressor is designed for intermittent use, while the other will be best for ongoing applications.
If you are performing an occasional job in your home garage, the single stage compressor is going to provide what you need. However, if you are looking to run the compressor full-time, you might consider upgrading to the two-stage model instead.
5. Price
What is better, a single stage or two stage air compressor in terms of price? There's no question that the two-stage compressor is going to cost more than the single-stage upfront. However, you will perform more maintenance on it, and there are more parts that could break, leading to a more considerable cost down the road. With that said, the efficiency of the two-stage compressor can help you save money across the long haul.
6. For Metal Works
If you are a metal worker, you need to look at the single stage versus two stage air compressor. In most cases, the single stage compressor is best suited for metal work. If you work with metal, you can use a single stage compressor for shearing and grinding your pieces. It’s also suitable for riveting and ratcheting materials.
7. For Auto Assembly & Maintenance
If you are deciding whether the single or two stage air compressor is right for your automotive applications, you need to think about what you will be doing. In many cases, the two-stage compressor is ideal, especially if you are going to be working continuously. However, you must also think about how much horsepower is needed. Both compressors are good for lifting, screwing, and painting projects.
People Also Ask (FAQs)
Does the tank size matter in the air compressor?
The tank size doesn't make a difference in terms of pressure or capability. However, the larger the tank is, the more air it will hold. This allows you to run the compressor longer without it needing to refill the tank, so it cuts down on your time waiting.
How do I know if my air compressor is two stage?
It’s simple to tell the difference between the single stage and two stage air compressor. If air gets sucked into the piston and sent immediately to the tank through a pipe, you have a single stage unit. However, if air is sucked in and sent to another piston through a pipe, you have a two-stage compressor.
Will a 2 gallon air compressor run an impact wrench?
Pneumatic impact wrenches need certain requirements to run properly. Usually, you want an air compressor with 4 to 5 CFM (cubic feet per minute) at 90 PSI (pounds per square inch). It’s also recommended that you have a 20-gallon tank to avoid any delay, but that’s not necessary.
How do I increase the CFM of an air compressor?
Whether you have a single stage or two stage air compressor, you can affect the CFM when needed. Consider decreasing the pressure or adding a second compressor to gain more CFM. You can also add another air receiver tank if needed.
Conclusion
Which is better – a single stage or two stage air compressor? It depends on your needs. If you are looking for something reliable and the price isn’t an option, you will likely do better with the two-stage compressor. However, there’s nothing wrong with using a single-stage compressor for most general projects.