Air Compressor Pump And Motor

If you have any amount of air tools in the garage then you will need a portable air compressor to run them. Most garage hobby mechanics will choose portables over a stationary because they can be used in lots of different applications. A portable unit gives you the option of moving the compressor out the garage and hooking up a nail gun to work in the house or yard.

Electric or Gas Powered

They are either powered by an electric motor or a gas engine for more professional models. The pump puts the compressed air into a storage tank and then a hose is hooked up to power your air tools. Most portable air compressors are oil lubricated pumps. The oil lubricated models are quieter and generally last longer than oil free models but will require you to change the oil periodically. An oil free model is easier to deal with but will not last as long with prolonged use.

Arrangement of the Air Tank

Portables generally come in different tank configurations. There are basically two different styles on the market. Pancake style models have the motor and compressor mounted on top of a pancake shaped storage tank. You will mostly see these units running a nail gun. They are popular for this application because you can quickly pick one up and move it around. There is also a twin stack arrangement of the storage tanks. These have two long, narrow tanks mounted next to each other with a wheel mounted in the middle. Both of these types of models are electric powered and will run on a 15 amp house circuit. I would recommend staying away from anything bigger for you r house because they will pop your breaker trying to draw too many amps.

How Big of a Compressor Do You Need?

Choosing the right size is critical to running your air tools. The most important factor is the storage tank size not horsepower or air pressure. This is where you have to ignore the slick salesmanship on the box. The larger the capacity of the storage tank the longer you can run your air tool. Impact wrenches for example use a lot of air to run them and a smaller tank will quickly run out of air before the pump can refill it. Air volume is really the limiting factor. Almost all air tools require around 90 psi of pressure and all these units will do that. A nail gun for example only requires about 2.2 CFM to run compared to angle grinder that needs anywhere from 8 to 30 CFM. This is why a pancake style is fine for a nail gun but if you are running impact wrenches and air grinder you will need a larger model.

Sizing Chart

Air Tool

Air Pressure (psi)

Air Volume (cfm)

Nail Gun 100 2 - 3

Staple Gun 100 2

Orbital Sander 90 4 - 15

Jigsaw 90 7 - 28

Angle Grinder 90 7 - 30

Spray gun 30 - 50 8 - 10

Impact Wrench 90 6 - 10