You may or may not already be aware that not all air compressors are used for all jobs! They vary in both size and of course their power level. The best way to estimate what you will need is to take a careful look at the power requirements of any of the air tools you plan on using. Then its a simple matter of choosing one that is slightly more powerful than youll need so that you have the ability to purchase an air tool that needs a bit higher power level.

For example, one common air tool is the rotary screw compressor. When looking for a rotary screw compressor, you are faced with an array of choices. If you want a powerful screw compressor, don’t choose a cheap one. Those are only good for occasionally pumping up your tires with air.

Sometimes compressors are rated by HP or horsepower. But the HP listing can be misleading. What is important is the amount of power the compressor draws. It’s not uncommon for there to be an inflated value for the HP.

A better value to look at is the PSI. This means pounds per square inch. Most air tools need 90 PSI to function. But if the compressor has a listing of 125 to 135 PSI, it will not be able to properly run the 90 PSI air tool. This is because what the PSI is really measuring is shut off pressure, and that value does not account when there is a loss of pressure in the line. If you want to get the best efficiency from your 90 PSI tool, think about a compressor that has two-stage pressure shut off. The first stage will shut off at 90 PSI, and the second stage will wait until 175 PSI to shut off.

Also think about cubic feet per minute (CFM). For most air tools you’ll find in the store today, a CFM of 4 to 6 is common. This will make your life easier because at 90 PSI you should be getting exactly 3 to 4 HP. The CFM is a measurement of how much air moves through the system.

Tank size on a compressor may be important to you depending on how you wish to use your air compressor. If your work requires you to use it in short bursts, then the typical 30-gallon tank and a normal pump and motor is more than fine. If however, you wish to use it heavily, you would do better with a bigger tank and much stronger pump and motor, taking into consideration air that is stored in the tank.

Because of this you may see professional contractors running multiple air tools at the same time, with the knowledge that using a compressor with a rating of 150 PSI is a better choice for long-term continual use.

Unlike portable compressors, truck mounted ones use the truck to power the compressor. The problem is that you have to keep the truck running in order for the compressor to work. For the contractor who needs to have the compressor running for a long period of time, the better choice is an affordable compressor or possibly one that is mounted on a deck. Just like truck mounted compressors, deck mounted ones are set on a truck’s bed that is removable, which makes it possible to leave the compressor on-site as opposed to having to drag it back and forth for each day of consecutive work.

Also you can find compressors that are electrically and gas powered. If you think you’re going to be working on a site that does not have electricity, then go with a gas powered compressor.