How to Buy an Air Compressor

An air compressor is one of the main sources of power in many shops and one of the most expensive investments. There are many different kinds of air compressors to choose from, and there are some things to think about before you decide which one to buy.

Difficulty:

Moderate

Instructions

1. Decide how much money you want to spend. Inexpensive units don't last as last long, and you usually get what you pay for. If you buy one too small for the jobs you plan to do, you won't be productive. If you buy one that's too large, you're wasting your money and resources.

2. Determine how you plan to use your compressor. A single-stage piston compressor is sufficient for light duty work around your home. It uses a storage tank and produces up to 150 PSI. The two-stage piston is a heavy duty, commercial air compressor and delivers over 150 PSI. This is a good choice for continuous use in a large shop with multiple tools operating simultaneously. The final choice is the compact variety, which is small, light and doesn't have a storage tank. It must run continuously and is useful to run small caulk, glue or spray guns, and to air up tires and sports equipment.

3. Gauge how many gallons the receiver tank should be by the type of tools you are going to use. If you are going to use a sander, impact wrenches and other tools that require sustained air pressure, you'll need a larger tank. For smaller tools that use short, quick shots of air, the smaller tank will work. Select the tool that requires the highest CFM and the highest PSI, and then add 50 percent to the CFM number. You will need a tank large enough to deliver that amount of CFM for your tools to work properly.

4. Figure out how much horsepower is necessary for the work you're going to do. Most motors range from 1.5 to 6.5 horsepower. A higher horsepower motor delivers more PSI and can carry a heavier load of work, but the CFM is the most important consideration.

5. Find out whether your air compressor is going to be stationary or portable. If you're going to move it around or transport it, consider the size, weight and power source. The units with higher pressure and volume are larger and heavier.

6. Consider the source of power available to you. The electric air compressors are the most efficient in terms of costs and maintenance. However, a gasoline model is more portable and allows more choices as to where you can use them.

Tips & Warnings

• Buy your air compressor from a reliable manufacturer that offers a good warranty and a full line of parts and services.

• The PSI (pounds per square inch) is the force of the air; CFM (cubic feet per minute) is the volume.

• Don't ever use a gas-powered air compressor in a confined area because of the danger of carbon monoxide poisoning.