How to Choose a Compressor

Choosing the Right Compressor for the Job

One of the most frequently asked questions we get is, “What kind of compressor do I need?”

When choosing a compressor, there are many different factors to consider. Some of them include price, noise levels, motor size, oil vs. oil less, tank size (if any), space, portability, air pressure, and air volume. There are also other factors, but for this example, we will focus on these.

So, let’s take each of these, one by one and try to make some sense out of all of this.

Price – Is this ever not a factor? Here is a quick rundown when it comes to compressors in general. Bigger costs more when it comes to tank type compressors.  Smaller costs more when it comes to tank less, portable models. Quieter also costs more. The quieter the compressor, the more expensive it usually is to purchase.

Noise Levels – Noise is always a factor when choosing a compressor. Most people want a compressor to be as quiet as possible, but the quieter the compressor, the higher the price usually is. As a work a round, some will put their compressor as far away from their workspace as possible then run an air hose into the workspace. This only works if you have somewhere to put the compressor outside of your workspace and a long air hose.

Motor Size – Bottom line – bigger motors pump more air in shorter time. This means the air volume output will be greater, allowing you to run more tools. It also means the air tank will fill up quicker, meaning you will not have to listen to the compressor run as long. However, the bigger the compressor motor is, the more space it will require and it will also be heavier to transport. If you are going to travel to events with your compressor, you will want to choose a compressor that is big enough to do the job, but not so big that you cannot transport it easily.

Oil vs. Oil less – In my opinion, an oil motor will outlast an oil less and is usually quieter. However, an oil less motor is very nice if you are going to be moving it around. If you are planning on traveling with your compressor, it is nice not to have to worry about oil spilling out. Therefore, if you are going to put your compressor in a shop and leave it, choose an oil type motor. But, if you are going to travel with your compressor, an oil less might be a better solution.

Tank vs. Tank less – Tank less compressors are great for portability and traveling. However, a tank type compressor controls moisture better and as soon as the tank fills up, you don’t have to listen to it until the air pressure goes down. Again, you need to consider the amount of traveling you will do with your compressor. Portable, tank less compressors (especially oil less) are great for traveling to events such as trade shows. But, if you are going to work out of a shop, leaving your compressor in one place, you would be wise to choose a compressor with as big of a tank as you can afford, or fit into your shop. The bigger the tank, the less you will have to listen to the compressor run and the less the motor will have to work to keep up with you as you engrave or sandblast.

Space Requirements – Usually this in only a factor if you have decided on using a tank type compressor. Compressors are available in many different shapes and sizes including horizontal, vertical, hot dog style, pancake etc. The type you choose will depend on the space where you are putting your compressor. I would recommend getting the biggest one you can afford or fit into your workspace.

Portability – I think you get the point by now.

Air Pressure and Air Volume – This is where most people get confused when deciding on a compressor. You need to realize that air pressure is different from air volume. Two separate things completely. When choosing the right compressor for the job, you need to consider both pressure and volume.

A compressor might be able to produce 100 psi of pressure, but the volume might not be sufficient to keep up with the tool you are using. Every tool requires a certain amount of air pressure and a certain amount of air volume. One means nothing without the other.

Most compressors say right on the label how much air volume they are able to produce at a certain pressure.  A compressor might be able to pump up to 125 psi, but that doesn’t necessarily mean it will run the tool you need to run. This is where volume comes into play.

Let’s look at a compressor label.

Take a look at the SCFM field – this is the volume this compressor can put out at a certain pressure.

You will see that it says, 6.5 @ 40 psi. This means as you are using 40 psi (pounds per square inch – pressure), the pump will continue to produce 6.5 cubic feet per minute of air volume. As you increase the pressure you are using to 90 psi, the pump will only produce 5.5 cfm of air volume. As you use more pressure, the pump produces less volume.

You can also see on the label that this compressor is a 2 hp motor, will pump a maximum of135 psi and has a 26 gallon tank. This is a compressor that I use in the shop that is not transported and pumps a lot more air than needed to run Profitable Hobbies high speed engraving or micro sandblasting equipment.

Here are the recommended air requirements for Profitable Hobbies Systems. If you make sure the compressor label says at least this, you will be fine, regardless of the motor size, tank type, or any of the other factors discussed above.

High Speed Engraving System – 4.0 scfm at 40 psi.

Micro Sandblasting System – 4.3 scfm at 40 psi. I also recommend a tank type compressor for micro sandblasting to control moisture better, however, we have had some success using our small, portable models for sandblasting when traveling is required. A tank type compressor is recommended for sandblasting, but you can get by with a portable model, as long as it can meet the air delivery requirements.

Here is the compressor we have used for many years at trade shows and other public events. We designed a quiet case for it with a built in fan and power chords for convenience and functionality. We feel that it is a good balance between price, portability, longevity, noise and space. Again, this compressor is designed for those wanting to travel to events, or where noise and space is a factor.

The Thomas Compressor is a commercial grade, portable compressor that has passed every test Profitable Hobbies has put it through. (And there have been some tough tests as we have traveled all over the country with these!)

It is fully enclosed in an aluminum case for portability. The motor is oil less, there is no tank. There is a strap inside the box which keeps the compressor in place. There is also a built in fan in the one side and a vent in the other. This allows you to close the case during operation without over heating.  This compressor pumps out enough air to operate our high speed engraving systems for long durations and micro-sandblasting system for smaller projects. Again, we recommend a tank type compressor for larger sandblasting projects.

The motor is re-buildable, should the need ever arise, saving you the cost of replacing the compressor.

Profitable Hobbies provides a full one year limited warranty on this compressor.

The Thomas Compressor is available for purchase in Profitable Hobbies Online Store.

If you have additional questions, please don’t hesitate to contact us at 1 800 624-7415. We will do our best to answer any questions you might have.

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4 Responses to How to Choose a Compressor

  1. Lance Larson December 22, 2009 at 10:23 am #

    This is great information for all. This was the biggest problem I had when I started. The first compressor I bought was too small. All trial & error but I finally found one.

    Thanks for the info……

    Lance Larson

    L Larson Studio
    Casa Grande, AZ

  2. Juanita Young December 31, 2009 at 11:40 pm #

    I have to tell you I have used compressors in my custom frame shop for 17+ yrs….went thru 3 or 4 of them….in that time frame….this Thomas Compressor so surpasses anything I have ever used….it is wonderful…quiet…just cannot believe it…so nice to use…well worth the cost…

    it will be awhile before we get this system paid for…and I could of bought a lot cheaper compressor….I am so glad I did NOT do that and went with Tammy’s recommendation…there is nothing on the market to begin to equal this compressor….

    Juanita Young….in Kenai, Alaska

  3. Jose Valencia January 1, 2010 at 10:04 pm #

    Another very important thing to consider when buying a compressor for your workshop is the following:
    A compressor with a vertical tank will take less space in your workshop than one with an horizontal tank.
    There are some compressors that are piston driven and others that are belt driven.
    I have had both. The piston driven pumps have a very high pitch noise, and they will drive you crazy, even if they are stored in a garage and you use a long hose to your workshop. I sold that compressor at a loss within a week.
    I would strongly recommend a vertical tank compressor with a belt driven pump. They seem quieter, the noise is at a lower frequency and it’s more tolerable.
    You will have to change the oil on the motor, but they will last longer.
    (The first time you change the oil, install a 2″ or 3″ piece of pipe on the drain so you won’t get the oil all over the motor case next time you’ll drain it!)
    I have a 26 gallon vertical tank belt driven compressor. You can get them at Lowes or Home Depot, just shop around for the price.
    Feel free to contact me if you have any questions.

    Jose Valencia
    Jose Valencia Studio
    P.O. Box 8234
    Phoenix, AZ 85066


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