No matter how good an air compressor is, it can’t do all jobs. Compressors have different sizes and levels of power. In order to figure out which air compressor is right for you, you first need to determine the power requirements for your air tool. Once you’ve done that, then make sure to choose an air compressor that has a bit more power than your tool requires, so that when you buy your next air tool, even if it needs a little more power, it will work.

Ordinarily you will probably run across portable rotary screw compressors. There will be a dizzying assortment of choices to make. The cheap ones are just that, cheap ones, thus you should probably stay away from those, unless all you want to do is put air into your tires occasionally.

Air compressors are sometimes rated by horsepower or hp. Dont be swayed by the hp listing. It all depends on how much power it draws. Often the hp listed is inflated.

Instead, you should look at the PSI, which stands for Pounds per Square Inch. Generally, youll require 90 PSI for most air tools. However, an air compressor listed at 125 to 135 PSI will not run that air tool properly. You see, the PSI is the shut-off pressure, and even if an air compressor shuts off at 100 PSI, this does not take into account something called pressure loss in the line! Thus, to work at peak efficiency with 90 PSI tools, you should really consider a two stage pressure shut off compressor, that shuts off the first stage at the 90 PSI, but the second stage wont shut off until it reaches 175 PSI.

Next you will take into account the “cubic feet per minute” or CFM. The majority of air tools manufactured today will require 4 to 6 CFM. Not a big deal here, since at 90 PSI you will be getting 3 to 4 exact horsepower. CFM merely tells you how much air is being moved.

Tank size is also very important when considering your goals in using your compressor. It is just fine to use a regular part and motor and the standard tank of 30 gallons if your job requires only short bursts. But you want to go with a smaller tank that has a more powerful pump and motor, paying attention to the air stored in the tank, if you intend to use your compressor heavily.

This is why you’ll often see contracting professionals using multiple air tools simultaneously; they know that a 150 PSI rated compressor is a superior choice when using the compressor on a long-term, continuous basis.

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 there are both electrical and gas powered compressors. If you are likely to be on a site that lacks electricity, then the gas powered compressor is your best choice.