The capacity and type of compressor will depend on how much you will use it and if you will have any air tools. An air compressor is a very handy tool, one that you wonder how you got along without after you've had it for a while.

There are two types of compressors, oil less and oil bath. The oil less are less expensive, portable and not as long lasting if used often. They are commonly seen on the smaller units used by contractors for their portability. They are 2 - 4 hp direct drive motors, 4 - 10 gal, and will run nail guns and the like. Prices are in the $150 -$250 range. They are available in pancake styles as well as conventional tanks and uprights. They can be plugged into most household outlets.

In the $250 - $400 range are better oil bath, 20 gal units with 4 HP belt driven compressors. They push the capacity of all but the 20 amp outlets. They are longer lasting, able to furnish enough air for most tools, and spray guns. They are less portable, and work very well in a garage for a multitude of projects.

Vertical tank models with 5 & 6 HP, 220 V motors of 40 - 60 gal sizes are used for serious mechanics. They are also available with two stage compressors that are more efficient and produce higher pressures.

Any of these units will produce about 90 - 100 psi minimum, and will air tires. The main criteria when buying a compressor is the CFM, the cubic feet per minute of air that it compresses. The higher the amount, the more useful it is and the more expensive it becomes. The small oil less models put out around 3 - 5 CFM, enough for your tires. The middle units typically compress about 5 -9 CFM, and are large enough to spray paint, use an impact gun etc. The large compressors have enough capacity to run an air line wide open and still hold pressure.

The middle priced ones are sold by every hardware store, Sears, big box stores etc. They do a fine job, and you can use them for spray painting. I have all three. The portable one is ideal to bring into the house when using finishing nailers for wood working projects, or to take into the barn when I have to use a framing gun. It is a 4 hp 10 gal oil less and cost ~$175.

My first compressor was a Sears 20 gal 4 HP that I used very hard while shooting fiberglass materials. It could not keep up with shooting fiberglass gel coatings. It was replaced with a 60 gal unit that can run two air tools at the same time.

I would recommend the 4 hp oil bath type with belt driven compressor and a 20 gal tank. You won't out grow it as fast, when you realize how useful the compressors are. Installing synthetic oil in the compressor will make them last a life time. My Sears is over 35 years old and still going strong.

Gard