By Matt Weber

Air compressors provide a single power source for a wide assortment of tools.

There are three very good reasons why air compressors are so popular among professionals and DIY'ers alike; they're versatile, economical and powerful. An air compressor provides a single power source for a wide variety of tools that tackle everything from woodworking and metalworking to painting and mechanical work.

There's quite a variety of compressor sizes and capacities. Choose from small inflators, more powerful portable air compressors and professional-grade stationary models. The most popular units among DIY'ers are portable units that can do everything an inflator can, and much more. They can also be toted to the jobsite while still providing ample power. A portable air compressor is a great household tool that can inflate tires, operate an air brush kit and power short-burst tools like nailers and staplers.

Air Tool Value

Let's face it, you buy an air compressor to power your tools, and air tools offer some real advantages over electric tools. One of the biggest is that air tools do not require their own motor. This makes the tools more compact, lighter and easier to handle.

Air tools are also known for their long-lasting value. With electric tools, you have lots of small motors that can wear out. With air tools, you have a single powerful motor to run them all, and as a result air tools can perform for years and years.

Versatility is another advantage. Whether you're building a shed, painting a fence or fixing your car, you can easily interchange a variety tools at a single compressor, including a ratchet wrench, paint sprayer, angle nailer, finish nailer or impact wrench.

Whether you're building furniture
or framing a house,
short-burst tools like air nailers
make the work fly by.

Assessing Compressor Power

There seems to be a lot of confusion about what to look for when choosing the right size of air compressor. Many people assume the higher the horsepower rating, the more powerful the compressor. However, horsepower can be misleading. Much like two race cars with the same horsepower rating, one of the cars can still go faster. There are many other factors influencing how well the machine will perform other than horsepower.

When purchasing a compressor, many people also consider the air pressure or PSI (pounds per square inch) rating. But most air tools require 90 PSI to operate, and most air compressors produce at least 90 PSI. Extra pressure does not necessarily improve the performance.

What you really want to pay attention to is the air flow. Some tools consume more air than others. Nailers need only a short burst of air. Sanders, on the other hand, need massive air flow. Air flow is measured in cubic feet per minute (CFM). The greater the air flow, the bigger the power output. When selecting an air compressor check the CFM rating of the most powerful air tool you plan to operate. Then choose an air compressor with a CFM rating that exceeds that of the tool. If the air flow isn't adequate then the tool won't operate properly. Many nail guns require less than 1 CFM. Most air tools require 3 to 6 CFM. For sanding or sandblasting applications you may require an industrial compressor that produces 6 to 13 CFM.

Also, don't be confused by manufacturers who give higher CFM ratings at different pressures. Since most air tools operate at 90 PSI, you should primarily be concerned with how much CFM you will get at 90 PSI.

More to Consider

The next factor is tank size. Sizes are usually listed in gallons. However, don't confuse larger tank size with more run time for tools. For intermittent use, a big tank is fine. But for continuous use, the compressor will need a smaller tank with a big pump and motor. If the power source is strong enough, you should not run out of air. Of course, the bigger the pump and motor, the bigger the compressor's price tag. For intermittent use, you can save money by choosing an air compressor with a smaller pump/motor and a larger tank.

Tank design is also something to consider, because what you own, you must store. Some units feature twin tanks, giving the compressor a box-like shape. Some tanks are round and flat, called a "pancake" design. Some tanks are designed horizontally, while others stand vertically to occupy a smaller footprint.

Another consideration: Maintenance. Oil-free compressors have sealed bearings and require less maintenance than oil-lubricated compressors. Oil-free compressors usually have enough power for homeowner applications. Most heavy-duty, professional-grade compressors are oil-lubricated, but these compressors require regular oil changes.

Air compressors are also available as single-stage or two-stage models. Single-stage models are the most common for home usage. Two-stage compressors are usually found on commercial heavy-duty compressors, but are good choices for continuous-use applications.

When selecting a portable compressor, consider factors such as the unit's weight and whether or not it has wheels. And when it comes to compressor weight, material matters.

When selecting a compressor,
consider its weight, size, portability,
maintenance requirements and power output.
Some compressors come with
amenities such as
dual hose outlets and accessory kits.

And don't forget to look for easy-to-read gauges and easy-access controls. Factors such as the number of hose outlets are also important. Some compressors also come as kits with accessories such as hoses, couplers and even air tools.

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